Budlong, M. (2000). SAMS Teach Yourself COBOL in 21 Days (3. Ed.). SAMS.
Lua i Stíl Chicago (17ú heag.)Budlong, Mo. SAMS Teach Yourself COBOL in 21 Days. 3. Ed. Indianapolis, Ind.: SAMS, 2000.
Lua MLA (8ú heag.)Budlong, Mo. SAMS Teach Yourself COBOL in 21 Days. 3. Ed. SAMS, 2000.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.