Super Charge Your Spectrum, David Webb

The Complete Spectrum ROM Disassembly, Dr Ian Logan & Dr Frank O'Hara

Spectrum Machine Language for the Absolute Beginner, William Tang

Pan Personal Computer, Sixty Programs for Sinclair ZX Spectrum

Write your own Fantasy Games - Commodore 64, Spectrum, Electron

Commodore 64 Machine code master, David Lawrence & Mark England

Acorn/BBC - Pan Personal Computer - Sixty Programs for the Electron

Spectrum Programmes, Volume 1, Nick Hampshire