Compute's Machine Language Routines for the Commodore 64

The Machine Language Book of the Commodore 64 * - Paper Back Edit

Machine Language for the Commodore 64, 128, and Other Commodore Computers - SB

Commodore 64 Machine Code Master - C64 Book

Mark Greenshields 40 Best Machine Code Routines for the Commodore 64 (Paperback)

Introducing Commodore 64 Machine Code BY Ian Sinclair - Coil Bound

Adventure Programs vintage Commodore 64 Manual 1983