S2 E8 - 40 YEARS since the Sinclair ZX81 (and how it indirectly helped give us the M1) | The Constant Geekery Podcast | Podcasts on Audible | Audible.com
Computer Puzzles for Spectrum and Z.X.81: Stewart, Ian, Jones, Robin: 9780906812273: Amazon.com: Books
S2 E8 - 40 YEARS since the Sinclair ZX81 (and how it indirectly helped give us the M1) | The Constant Geekery Podcast | Podcasts on Audible | Audible.com
Not Only 30 Programs for the Sinclair ZX81 (Retro Reproductions): Reproductions, Retro: 9781789825886: Amazon.com: Books
ZX81 - Timex Sinclair 1000 - Home Computer | Simplyeighties.com
Sinclair ZX Spectrum A Visual Compendiu: 9780993012938: Amazon.com: Books
The Century computer programming course: The complete guide to programming in Sinclair BASIC using the ZX81 and Spectrum microcomputers: Peter, etc. Morse: 9780712600729: Amazon.com: Books