#67: Lewis and Zak's Essential Discrete Mathematics for Computer Science. A succinct and high utility primer that'll no doubt be a reference in the future. https://press.princeton.edu/books/hardcover/9780691179292/essential-discrete-mathematics-for-computer-science
#68: Dennis P. Waters' Behaviour and Culture in One Dimension. Oooo, a fun read, especially as I was eyeing up the analog-continuous interface. Led me to think about product lines, too. https://1dimensional.com https://swellandcut.com/product-lines/