From Schmid.wiki

## Books

These books are available for free online and can also be purchased as physical books:

- Julius O. Smith III: Introduction to Digital Filters
- Julius O. Smith III: Mathematics of the Discrete Fourier Transform
- Miller Puckette: Theory and Techniques of Electronic Music
- [http://www.ece.rutgers.edu/~orfanidi/intro2sp/ Sophocles J. Orfanidis: Introduction to

Signal Processing]