APA (7th ed.) Citation

Heckel, P. (1991). The elements of friendly software design (New ed.). SYBEX.

Chicago Style (17th ed.) Citation

Heckel, Paul. The Elements of Friendly Software Design. New ed. San Francisco: SYBEX, 1991.

MLA (8th ed.) Citation

Heckel, Paul. The Elements of Friendly Software Design. New ed. SYBEX, 1991.

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