APA (7th ed.) Citation

Wren- Hilton, M. (1982). The Zx81 add on book. Shiva Publishing.

Chicago Style (17th ed.) Citation

Wren- Hilton, Martin. The Zx81 Add on Book. England: Shiva Publishing, 1982.

MLA (9th ed.) Citation

Wren- Hilton, Martin. The Zx81 Add on Book. Shiva Publishing, 1982.

Warning: These citations may not always be 100% accurate.