Clipper programming guide / Rick Spence. Spence, Rick. Clipper (Computer program language) QA76.73.C23 S64 1991 001.642 20 SPC "Version 5"--Cover. Includes index. San Marcos, CA : Microtrend Books, c1991. c1991. 1991 Text xxviii, 610 p. : eng The Data based advisor series