diff --git a/org.pathvisio.lib/src/main/java/org/pathvisio/libgpml/model/GPML2013aReader.java b/org.pathvisio.lib/src/main/java/org/pathvisio/libgpml/model/GPML2013aReader.java
index 9171599..bf5534f 100644
--- a/org.pathvisio.lib/src/main/java/org/pathvisio/libgpml/model/GPML2013aReader.java
+++ b/org.pathvisio.lib/src/main/java/org/pathvisio/libgpml/model/GPML2013aReader.java
@@ -370,7 +370,7 @@ protected void readPublicationXrefs(PathwayElement pathwayElement, Element e,
 				// if source is an url, also set as citation urlLink
 				String urlLink = null;
 				if (source != null) {
-					if (source.startsWith("http") || source.startsWith("www")) {
+					if (source.startsWith("http") || source.startsWith("www") || source.startsWith("doi")) {
 						urlLink = source;
 					}
 				}