Gaya APA

Overbeek, R, A., Singletary, W, E. (1986). Introduction To Cobol A Primer and Programming Guide . California: Addison-Wesley Publishing Company.

Gaya MLA

Overbeek, Ross, A.., Singletary, W., E.. "Introduction To Cobol A Primer and Programming Guide". California: Addison-Wesley Publishing Company, 1986. Text.