"A Great Old-Timey Game-Programming Hack" - Tom Moertel - 12/14/2013 Blog
"Optimizing 6809 Assembly Code: Part 3 - Stack Blasting and Self Modifying Code" - 9/16/2017 - nowhereman999.wordpress.com
"CoCo (6809) Assembly on a modern computer" - 6/19/2017 - nowhereman999.wordpress.com
6809 Assembly Language Programming - Leventhal - 1981
Assembly Language Graphics for the TRS-80 Color Computer - Don Inman, Kurt Inman with Dymax - 1983
"Dragon Machine Language for the Absolute Beginner"- Reyden - 1983
"Programming in 6809 Assembly" - Lesson 12 PONG - by Steve Bjork 11/03/2018 and SPACEWAR 2.0 (RPN) variant
CoCo Town - 2023 - YouTube
Assembly by George - 2023 - YouTube