https://www.youtube.com/playlist?list=PLDDGPdw7e6Aj0amDsYInT_8p6xTSTGEi2
https://www.youtube.com/playlist?list=PLHXZ9OQGMqxersk8fUxiUMSIx0DBqsKZS
https://www.youtube.com/playlist?list=PLl-gb0E4MII0sGLCJeqDB3y63HZ6lM5LJ
https://www.youtube.com/playlist?list=PLl-gb0E4MII0CsY4AE2xeZwZIkds3jIGs
https://www.youtube.com/results?search_query=discrete+math
https://www.amazon.com/2000-Solved-Problems-Discrete-Mathematics/dp/0070380317/