diff --git a/UML-Guidelines.md b/UML-Guidelines.md
index c81268e..9e628c2 100644
--- a/UML-Guidelines.md
+++ b/UML-Guidelines.md
@@ -19,11 +19,42 @@ Here are some recommended resources:
 
 Online:
 
+Introduction to concepts:
+https://medium.com/nerd-for-tech/principles-of-object-oriented-design-556edf6987be
+https://www.oodesign.com/design-principles
+https://www.educative.io/courses/grokking-the-low-level-design-interview-using-ood-principles
+https://www.educba.com/class-diagram/
+https://blogs.sap.com/2022/05/27/abap-oo-design-7-basic-oo-principles-summary/
+
+Design guides:
+https://www.visual-paradigm.com/guide/uml-unified-modeling-language/uml-class-diagram-tutorial/
+https://creately.com/blog/software-teams/class-diagram-tutorial/
 
 
 
 Books:
 
+Required:
+Godot Engine Game Development
+UML Distilled 3rd Edition
+Design Patterns - Coding
+
+Recommended:
+Learning UML 2.0 - O’Reilly
+
+
+
+Also Helpful:
+Universal Principles of Design (Lidwell) - UI/UX
+Game Programming Patterns - Game Design
+UML Modelling Language
+
+
+UML For Mere Mortals
+UML for Dummies 
+
+
+