https://hypertextbook.com/
hypertextbook
Free books to read and enjoy online. General interest hypertext-books and technical hyper-textbooks — physics, mathematics, cycling, education, media,...
hypertextbook
https://physics.info/
The Physics Hypertextbook
The Physics Hypertextbook is a reaction to three big problems with textbooks: lack of writer's voice, layouts that reduce readability, and outdated economics.
the physicshypertextbook
https://www.jick.net/htb/
Science 1 HyperTextBook
sciencehypertextbook