Cowan, D., Dirksen, P., Graham, J. An introduction to cobol with watbol : a structured programming approach. Ontario: Watcom Publ., 1976 400 p. : ill. 0-919884-03-2.
Cowan, D., Dirksen, P., Graham, J. An introduction to cobol with watbol : a structured programming approach. Ontario: Watcom Publ., 1976 400 p. : ill. 0-919884-03-2.
Cowan, D., Dirksen, P., Graham, J. (1976) An introduction to cobol with watbol : a structured programming approach, Ontario: Watcom Publ. 400 p. : ill. 0-919884-03-2.
Cowan, D., Dirksen, P., & Graham, J. (1976). An introduction to cobol with watbol : a structured programming approach. Monogr.. Ontario: Watcom Publ., 400 p. : ill.
Cowan D, Dirksen P, Graham J. An introduction to cobol with watbol : a structured programming approach: Monogr.. Ontario: Watcom Publ.; 1976. p. 400 p. : ill. ISBN: 0-919884-03-2.
