diff --git a/docs/documentation/android/javaClasses.md b/docs/documentation/android/javaClasses.md
index dba5fbd..f7b2bb0 100644
--- a/docs/documentation/android/javaClasses.md
+++ b/docs/documentation/android/javaClasses.md
@@ -110,4 +110,5 @@ public class MyClass {
 
 ## Sources 
 
-* https://www.w3schools.com/java/java_modifiers.asp
+* https://www.w3schools.com/java/java_modifiers.asp explanation of modifiers
+* https://en.wikipedia.org/wiki/Syntax_diagram For syntax diagram
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