Which books OR online courses are best for Audio Industry

Warning, this is math heavy as it was designed for engineering students: 


https://amzn.to/2ICQgaV

Merlin Blencowe and Morgan Jones have fantastic books on amplfier design (tubes/valves).

As an introductory primer on tube amp design, you can watch the You Tube video of Roger Modjeski’s (Music Reference) 90 minute talk at the 2015 Burning Amp Festival. It’s free! Also on You Tube are videos posted by Roger himself, wherein he discusses pre-amp design.

I found this course online by university of Rochester on Coursera a free course and If want certificate pay $49. Any thing like this courses offered by Universities? https://www.coursera.org/learn/audio-engineering/