Friedman, F. L. (1982). Problem solving and structured programming in WATFIV. Addison-Wesley.
Cita Chicago (17th ed.)Friedman, Frank L. Problem Solving and Structured Programming in WATFIV. Massachusettes: Addison-Wesley, 1982.
Cita MLA (9th ed.)Friedman, Frank L. Problem Solving and Structured Programming in WATFIV. Addison-Wesley, 1982.
Atenció: Aquestes cites poden no estar 100% correctes.