Davis, G. B., & Litecky, C. R. (1987). Structured cobol: A step by step approach. McGraw-Hill.
Cita Chicago (17th ed.)Davis, Gordon B., i Charles R. Litecky. Structured Cobol: A Step by Step Approach. New York: McGraw-Hill, 1987.
Cita MLA (9th ed.)Davis, Gordon B., i Charles R. Litecky. Structured Cobol: A Step by Step Approach. McGraw-Hill, 1987.
Atenció: Aquestes cites poden no estar 100% correctes.