Triance, J. (1981). COBOL Programming. NCC Pub.
Chicago-čujuhus (17. p.)Triance, J. COBOL Programming. Manchester: NCC Pub, 1981.
MLA-čujuhus (9. p.)Triance, J. COBOL Programming. NCC Pub, 1981.
Muitte dárkkistit čujuhemiid riektatvuođa, ovdal go geavahat daid iežat deavsttas.