Electrónica

https://archive.org/stream/electronics_-_Forrest_Mims-engineers_mini-notebook_basic_semiconductor_circuits_/electronics%20-%20Forrest%20Mims-engineer%27s%20mini-notebook%20basic%20semiconductor%20circuits%20%28radio%20shack%20electronics%29#page/n22/mode/1up

https://www.forrestmims.org/biography.html

https://hackaday.com/2017/01/18/forrest-mims-radio-shack-and-the-notebooks-that-launched-a-thousand-careers/

Op-Synth

https://docs.google.com/viewer?url=http://www.tofstuff.com/uploads/Op-Synth/livret.pdf
http://op-synth.tofstuff.com/
http://tof.t-o-f.info/?/projects/op-synth/
https://github.com/thomasfredericks/Op-Synth