EDWARDS, P. (1987). Advanced cobol. Macmillan.
Lua i Stíl Chicago (17ú heag.)EDWARDS, Perry. Advanced Cobol. New York: Macmillan, 1987.
Lua MLA (9ú heag.)EDWARDS, Perry. Advanced Cobol. Macmillan, 1987.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.