APA (7th ed.) Citation

(1990). X toolkit intrinsics reference manual: For version 11 of the X window system. O'Reilly Associates, Inc.

Chicago Style (17th ed.) Citation

X Toolkit Intrinsics Reference Manual: For Version 11 of the X Window System. Massachusetts: O'Reilly Associates, Inc, 1990.

MLA (9th ed.) Citation

X Toolkit Intrinsics Reference Manual: For Version 11 of the X Window System. O'Reilly Associates, Inc, 1990.