Spence, R. (1989). Clipper programming guide. Microtrend Books.
Cita Chicago (17th ed.)Spence, Rick. Clipper Programming Guide. San Marcos, CA: Microtrend Books, 1989.
Cita MLA (9th ed.)Spence, Rick. Clipper Programming Guide. Microtrend Books, 1989.
Atenció: Aquestes cites poden no estar 100% correctes.