diff --git a/src/main/dig/cmos/xor.dig b/src/main/dig/cmos/xor.dig
index 206f4a199..868e822f0 100644
--- a/src/main/dig/cmos/xor.dig
+++ b/src/main/dig/cmos/xor.dig
@@ -1,7 +1,12 @@
 <?xml version="1.0" encoding="utf-8"?>
 <circuit>
   <version>1</version>
-  <attributes/>
+  <attributes>
+    <entry>
+      <string>Description</string>
+      <string>Gate Diffusion Input (GDI) xor</string>
+    </entry>
+  </attributes>
   <visualElements>
     <visualElement>
       <elementName>In</elementName>
@@ -45,12 +50,22 @@
     </visualElement>
     <visualElement>
       <elementName>PFET</elementName>
-      <elementAttributes/>
+      <elementAttributes>
+        <entry>
+          <string>unidirectional</string>
+          <boolean>true</boolean>
+        </entry>
+      </elementAttributes>
       <pos x="460" y="160"/>
     </visualElement>
     <visualElement>
       <elementName>NFET</elementName>
-      <elementAttributes/>
+      <elementAttributes>
+        <entry>
+          <string>unidirectional</string>
+          <boolean>true</boolean>
+        </entry>
+      </elementAttributes>
       <pos x="460" y="240"/>
     </visualElement>
     <visualElement>
diff --git a/src/test/resources/dig/test/fet/cmos10TFullAdder.dig b/src/test/resources/dig/test/fet/cmos10TFullAdder.dig
index a3c0a4ae2..599a2933b 100644
--- a/src/test/resources/dig/test/fet/cmos10TFullAdder.dig
+++ b/src/test/resources/dig/test/fet/cmos10TFullAdder.dig
@@ -4,10 +4,7 @@
   <attributes>
     <entry>
       <string>Description</string>
-      <string>10 Transistor Full Adder
-The drivers represent p-channel fets. Needed to 
-avoid the resistance problem 
-(see https://github.com/hneemann/Digital/issues/30).</string>
+      <string>10 Transistor Full Adder</string>
     </entry>
   </attributes>
   <visualElements>
diff --git a/src/test/resources/dig/test/fet/cmosGDIFullAdder.dig b/src/test/resources/dig/test/fet/cmosGDIFullAdder.dig
index 09ba542eb..724d71931 100644
--- a/src/test/resources/dig/test/fet/cmosGDIFullAdder.dig
+++ b/src/test/resources/dig/test/fet/cmosGDIFullAdder.dig
@@ -55,17 +55,32 @@
     </visualElement>
     <visualElement>
       <elementName>NFET</elementName>
-      <elementAttributes/>
+      <elementAttributes>
+        <entry>
+          <string>unidirectional</string>
+          <boolean>true</boolean>
+        </entry>
+      </elementAttributes>
       <pos x="900" y="340"/>
     </visualElement>
     <visualElement>
       <elementName>PFET</elementName>
-      <elementAttributes/>
+      <elementAttributes>
+        <entry>
+          <string>unidirectional</string>
+          <boolean>true</boolean>
+        </entry>
+      </elementAttributes>
       <pos x="1100" y="300"/>
     </visualElement>
     <visualElement>
       <elementName>NFET</elementName>
-      <elementAttributes/>
+      <elementAttributes>
+        <entry>
+          <string>unidirectional</string>
+          <boolean>true</boolean>
+        </entry>
+      </elementAttributes>
       <pos x="1100" y="380"/>
     </visualElement>
     <visualElement>
diff --git a/src/test/resources/dig/test/fet/cmosMirrorFullAdder.dig b/src/test/resources/dig/test/fet/cmosMirrorFullAdder.dig
index 377a3d4a0..42626bc17 100644
--- a/src/test/resources/dig/test/fet/cmosMirrorFullAdder.dig
+++ b/src/test/resources/dig/test/fet/cmosMirrorFullAdder.dig
@@ -4,7 +4,7 @@
   <attributes>
     <entry>
       <string>Description</string>
-      <string>CMOS mirror adder</string>
+      <string>28T CMOS mirror adder</string>
     </entry>
   </attributes>
   <visualElements>
diff --git a/src/test/resources/dig/test/fet/cmosSERFFullAdder.dig b/src/test/resources/dig/test/fet/cmosSERFFullAdder.dig
index cc9013f23..c008e30ba 100644
--- a/src/test/resources/dig/test/fet/cmosSERFFullAdder.dig
+++ b/src/test/resources/dig/test/fet/cmosSERFFullAdder.dig
@@ -5,9 +5,9 @@
     <entry>
       <string>Description</string>
       <string>Static Energy Recovery Full Adder (SERF)
-The drivers represent n-channel fets. Needed to 
-avoid the resistance problem 
-(see https://github.com/hneemann/Digital/issues/30).</string>
+R. Shalem,  E. John,  and L. K.  John, 
+“A novel low-power energy recovery full adder cell”, 
+in Proc. Great Lakes Symp. VLSI , Feb. 1999, pp. 380 – 383.</string>
     </entry>
   </attributes>
   <visualElements>