ASHLEY RUTH. (1984). USING STRUCTURED COBOL,COBOL-2. WILEY EASTERN LTD.
芝加哥风格引文ASHLEY RUTH. USING STRUCTURED COBOL,COBOL-2. SINGAPORE: WILEY EASTERN LTD, 1984.
MLA引文ASHLEY RUTH. USING STRUCTURED COBOL,COBOL-2. WILEY EASTERN LTD, 1984.
警告：这些引文格式不一定是100％准确.