Detailed descriptions of play-practice-play theory and implementation:

https://www.mayouthsoccer.org/coaches/play-practice-play/

https://www.ussoccer.com/stories/2018/02/five-things-to-know-about-playpracticeplay

Practice plans using play-practice-play:

https://www.mayouthsoccer.org/coaches/session-plans/

And a podcast:

https://www.mayouthsoccer.org/mass-youth-soccer-grassroots-podcast/