APA (7th ed.) Citation

O'Reilly & Associates & O'Reilly, T. (1990). X toolkit intrinsics reference manual. The Associates.

Chicago Style (17th ed.) Citation

O'Reilly & Associates and Tim O'Reilly. X Toolkit Intrinsics Reference Manual. [Sebastopol, Calif.]: The Associates, 1990.

MLA (9th ed.) Citation

O'Reilly & Associates and Tim O'Reilly. X Toolkit Intrinsics Reference Manual. The Associates, 1990.