YORKEY RICHARD. (1981). REPLY REQUESTED 30 LETTERS OF ADVICE. ADDISON-WESLEY.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रYORKEY RICHARD. REPLY REQUESTED 30 LETTERS OF ADVICE. NEW YORK: ADDISON-WESLEY, 1981.
एमएलए (9वां संस्करण) प्रशस्ति पत्रYORKEY RICHARD. REPLY REQUESTED 30 LETTERS OF ADVICE. ADDISON-WESLEY, 1981.
चेतावनी: ये उद्धरण हमेशा 100% सटीक नहीं हो सकते हैं.