BUDLONG MO. (1998). TEACH YOURSELF COBOL IN 21 DAYS (2ND.). TECHMEDIA.
芝加哥风格引文BUDLONG MO. TEACH YOURSELF COBOL IN 21 DAYS. 2ND. NEW DELHI: TECHMEDIA, 1998.
MLA引文BUDLONG MO. TEACH YOURSELF COBOL IN 21 DAYS. 2ND. TECHMEDIA, 1998.
警告：这些引文格式不一定是100％准确.