EDWARDS, P. (1986). Cobol: A systems and structured approach. Burgess Communications.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रEDWARDS, Perry. Cobol: A Systems and Structured Approach. Minnesota: Burgess Communications, 1986.
एमएलए (9वां संस्करण) प्रशस्ति पत्रEDWARDS, Perry. Cobol: A Systems and Structured Approach. Burgess Communications, 1986.
चेतावनी: ये उद्धरण हमेशा 100% सटीक नहीं हो सकते हैं.