diff --git a/src/main/jastadd/Navigation.jrag b/src/main/jastadd/Navigation.jrag
index 444a59ed849eaa6de790a270a68c8ab169501b33..08173b5f0023392743fdd54dc9216de3debeb880 100644
--- a/src/main/jastadd/Navigation.jrag
+++ b/src/main/jastadd/Navigation.jrag
@@ -2,22 +2,40 @@ aspect Navigation {
   inh PetriNet PnObject.petriNet();
   eq PetriNet.getChild().petriNet() = this;
 
-  syn java.util.Collection<Place> Transition.incomingPlaces() {
-    java.util.Set<Place> incomingPlaces = new java.util.HashSet<>();
-    for (Arc incomingArc : getInArcList()) {
-      incomingPlaces.add(incomingArc.getSource().asPlaceNode().place());
-    }
-    return incomingPlaces;
+  syn java.util.Collection<Place> TransitionNode.incomingPlaces() {
+
+      java.util.Set<Place> s = new java.util.HashSet<>();
+
+      for (Arc incomingArc : getInArcList()) {
+          s.add(incomingArc.getSource().asPlaceNode().place());
+      }
+
+      for (TransitionNode ref : getReferencingTransitions()) {
+          s.addAll(ref.incomingPlaces());
+      }
+
+      return s;
   }
+  
+  syn java.util.Collection<Place> TransitionNode.outgoingPlaces() {
 
-  syn java.util.Collection<Place> Transition.outgoingPlaces() {
-    java.util.Set<Place> outgoingPlaces = new java.util.HashSet<>();
-    for (Arc outgoingArc : getOutArcList()) {
-      outgoingPlaces.add(outgoingArc.getTarget().asPlaceNode().place());
+    java.util.Set<Place> s = new java.util.HashSet<>();
+
+    for (Arc outgoing : getOutArcList()) {
+         s.add(outgoing.getTarget().asPlaceNode().place());
+    }
+
+    for (TransitionNode ref : getReferencingTransitions()) {
+         s.addAll(ref.outgoingPlaces());
     }
-    return outgoingPlaces;
+
+    return s;
   }
 
+  inh Page PnObject.ContainingPage();
+  eq Page.getObject().ContainingPage() = this;
+  eq PetriNet.getPage().ContainingPage() = null;
+
   syn boolean Node.isPlaceNode() = false;
   eq PlaceNode.isPlaceNode() = true;
 
@@ -38,6 +56,21 @@ aspect Navigation {
   eq Transition.transition() = this;
   eq RefTransition.transition() = getRef().transition();
 
+  syn boolean PlaceNode.isRefPlace() = false;
+  eq RefPlace.isRefPlace() = true;
+
+  syn boolean TransitionNode.isTransition() = false;
+  eq Transition.isTransition() = true;
+
+  syn boolean TransitionNode.isRefTransition() = false;
+  eq RefTransition.isRefTransition() = true;
+
+  syn RefTransition TransitionNode.asRefTransition() = null;
+  eq RefTransition.asRefTransition() = this;
+
+  syn Transition TransitionNode.asTransition() = null;
+  eq Transition.asTransition() = this;
+
   coll java.util.Set<PnObject> PetriNet.allObjects() [new java.util.HashSet()] root PetriNet;
   PnObject contributes this
     to PetriNet.allObjects()
@@ -57,4 +90,9 @@ aspect Navigation {
   Arc contributes this
     to PetriNet.allArcs()
     for petriNet();
+
+  coll java.util.Set<Page> PetriNet.allPages() [new java.util.HashSet()] root PetriNet;
+    Page contributes this
+    to PetriNet.allPages()
+    for petriNet();
 }
diff --git a/src/main/java/de/tudresden/inf/st/pnml/Main.java b/src/main/java/de/tudresden/inf/st/pnml/Main.java
index 7ea32ccbef31fe846ad13fcc1721368a57bf01b4..2e48446758f6cde17b37a74c5f7624ad72a293f5 100644
--- a/src/main/java/de/tudresden/inf/st/pnml/Main.java
+++ b/src/main/java/de/tudresden/inf/st/pnml/Main.java
@@ -2,6 +2,7 @@ package de.tudresden.inf.st.pnml;
 
 import de.tudresden.inf.st.pnml.jastadd.model.Marking;
 import de.tudresden.inf.st.pnml.jastadd.model.PetriNet;
+
 import fr.lip6.move.pnml.framework.general.PNType;
 import fr.lip6.move.pnml.framework.hlapi.HLAPIRootClass;
 import fr.lip6.move.pnml.framework.utils.ModelRepository;
diff --git a/src/main/resources/placeRefNet.pnml b/src/main/resources/placeRefNet.pnml
new file mode 100644
index 0000000000000000000000000000000000000000..5b9a62865dfefe19dc4242c57e1743fd16bac14a
--- /dev/null
+++ b/src/main/resources/placeRefNet.pnml
@@ -0,0 +1,110 @@
+<pnml xmlns="http://www.pnml.org/version-2009/grammar/pnml">
+    <net id="n-E2D0-BCF46-0" type ="http://www.pnml.org/version-2009/grammar/ptnet">
+        <name>
+            <text>minimal</text>
+        </name>
+
+        <page id="top">
+            <page id="p1">
+                <place id="p4">
+                    <name>
+                        <text>p4</text>
+                        <graphics>
+                            <offset x="0" y="-10" />
+                        </graphics>
+                    </name>
+                    <initialMarking>
+                        <text>1</text>
+                    </initialMarking>
+                    <graphics>
+                        <position x="30" y="50"/>
+                    </graphics>
+                </place>
+                <transition id="tRefIn">
+                    <name>
+                        <text>tRefIn</text>
+                        <graphics>
+                            <offset x="0" y="0" />
+                        </graphics>
+                    </name>
+                    <graphics>
+                        <position x="285" y="205"/>
+                    </graphics>
+                </transition>
+                <referencePlace id="rp1" ref="p-E2D0-BCF6F-2">
+                    <name>
+                        <text>rp1</text>
+                        <graphics>
+                            <offset x="0" y="0" />
+                        </graphics>
+                    </name>
+                    <graphics>
+                        <position x="20" y="20"/>
+                    </graphics>
+                </referencePlace>
+                <arc id="rin" source="tRefIn" target="rp1">
+                </arc>
+                <arc id="arc-p4-TRefIn" source="p4" target="tRefIn">
+                </arc>
+            </page>
+
+            <page id="p2">
+                <place id="p-E2D0-BCF6F-2">
+                    <name>
+                        <text>p0</text>
+                        <graphics>
+                            <offset x="0" y="-10" />
+                        </graphics>
+                    </name>
+                    <initialMarking>
+                        <text>0</text>
+                    </initialMarking>
+                    <graphics>
+                        <position x="30" y="50"/>
+                    </graphics>
+                </place>
+                <place id="p-E2D0-BCF9D-3">
+                    <name>
+                        <text>p1</text>
+                        <graphics>
+                            <offset x="0" y="-10" />
+                        </graphics>
+                    </name>
+                    <graphics>
+                        <position x="635" y="90"/>
+                    </graphics>
+                </place>
+                <transition id="t-E2D0-BCFAC-4">
+                    <name>
+                        <text>t0</text>
+                        <graphics>
+                            <offset x="0" y="0" />
+                        </graphics>
+                    </name>
+                    <graphics>
+                        <position x="300" y="50"/>
+                    </graphics>
+                </transition>
+                <transition id="t-E2D0-BCFBD-5">
+                    <name>
+                        <text>t1</text>
+                        <graphics>
+                            <offset x="0" y="0" />
+                        </graphics>
+                    </name>
+                    <graphics>
+                        <position x="285" y="205"/>
+                    </graphics>
+                </transition>
+                <arc id="e-E2D0-BCFCD-6" source="t-E2D0-BCFBD-5" target="p-E2D0-BCF6F-2">
+                </arc>
+                <arc id="e-E2D0-BCFDB-7" source="p-E2D0-BCF9D-3" target="t-E2D0-BCFBD-5">
+                </arc>
+                <arc id="e-E2D0-BCFF3-8" source="t-E2D0-BCFAC-4" target="p-E2D0-BCF9D-3">
+                </arc>
+                <arc id="e-E2D0-BCFFB-9" source="p-E2D0-BCF6F-2" target="t-E2D0-BCFAC-4">
+                </arc>
+            </page>
+        </page>
+    </net>
+</pnml>
diff --git a/src/main/resources/transitionRefNet.pnml b/src/main/resources/transitionRefNet.pnml
new file mode 100644
index 0000000000000000000000000000000000000000..95c2d8d49cb42fdb94ee2a5ca094d06b3d047825
--- /dev/null
+++ b/src/main/resources/transitionRefNet.pnml
@@ -0,0 +1,88 @@
+<pnml xmlns="http://www.pnml.org/version-2009/grammar/pnml">
+    <net id="n-E2D0-BCF46-0" type ="http://www.pnml.org/version-2009/grammar/ptnet">
+        <name>
+            <text>minimal</text>
+        </name>
+
+        <page id="top">
+            <page id="p1">
+                <place id="pRefSrc">
+                    <name>
+                        <text>pRefSrc</text>
+                        <graphics>
+                            <offset x="0" y="-10" />
+                        </graphics>
+                    </name>
+                    <initialMarking>
+                        <text>1</text>
+                    </initialMarking>
+                    <graphics>
+                        <position x="30" y="50"/>
+                    </graphics>
+                </place>
+                <referenceTransition id="rt1" ref="t-E2D0-BCFAC-4">
+                </referenceTransition>
+                <arc id="rin" source="pRefSrc" target="rt1">
+                </arc>
+            </page>
+
+            <page id="p2">
+                <place id="p-E2D0-BCF6F-2">
+                    <name>
+                        <text>p0</text>
+                        <graphics>
+                            <offset x="0" y="-10" />
+                        </graphics>
+                    </name>
+                    <initialMarking>
+                        <text>1</text>
+                    </initialMarking>
+                    <graphics>
+                        <position x="30" y="50"/>
+                    </graphics>
+                </place>
+                <place id="p-E2D0-BCF9D-3">
+                    <name>
+                        <text>p1</text>
+                        <graphics>
+                            <offset x="0" y="-10" />
+                        </graphics>
+                    </name>
+                    <graphics>
+                        <position x="635" y="90"/>
+                    </graphics>
+                </place>
+                <transition id="t-E2D0-BCFAC-4">
+                    <name>
+                        <text>t0</text>
+                        <graphics>
+                            <offset x="0" y="0" />
+                        </graphics>
+                    </name>
+                    <graphics>
+                        <position x="300" y="50"/>
+                    </graphics>
+                </transition>
+                <transition id="t-E2D0-BCFBD-5">
+                    <name>
+                        <text>t1</text>
+                        <graphics>
+                            <offset x="0" y="0" />
+                        </graphics>
+                    </name>
+                    <graphics>
+                        <position x="285" y="205"/>
+                    </graphics>
+                </transition>
+                <arc id="e-E2D0-BCFCD-6" source="t-E2D0-BCFBD-5" target="p-E2D0-BCF6F-2">
+                </arc>
+                <arc id="e-E2D0-BCFDB-7" source="p-E2D0-BCF9D-3" target="t-E2D0-BCFBD-5">
+                </arc>
+                <arc id="e-E2D0-BCFF3-8" source="t-E2D0-BCFAC-4" target="p-E2D0-BCF9D-3">
+                </arc>
+                <arc id="e-E2D0-BCFFB-9" source="p-E2D0-BCF6F-2" target="t-E2D0-BCFAC-4">
+                </arc>
+            </page>
+        </page>
+    </net>
+</pnml>