APA (7th ed.) Citation

Scheifler, R. N., Gettys, J., & Newman, R. (1988). X Window system: C library and protocol reference. Digital Press.

Chicago Style (17th ed.) Citation

Scheifler, Robert N., James Gettys, and Ron Newman. X Window System: C Library and Protocol Reference. Mass: Digital Press, 1988.

MLA (9th ed.) Citation

Scheifler, Robert N., et al. X Window System: C Library and Protocol Reference. Digital Press, 1988.