APA (7th ed.) Citation

Howling, B., & Pepper, A. (1988). A programmer's guide to GEM on the IBM PC and compatibles. Sigma.

Chicago Style (17th ed.) Citation

Howling, Barry, and Andrew Pepper. A Programmer's Guide to GEM on the IBM PC and Compatibles. Wilmslow: Sigma, 1988.

MLA (8th ed.) Citation

Howling, Barry, and Andrew Pepper. A Programmer's Guide to GEM on the IBM PC and Compatibles. Sigma, 1988.

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