Pitkin, W. B. (1940). The art of useful writing. Whittlesey House.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रPitkin, Walter Boughton. The Art of Useful Writing. New York: Whittlesey House, 1940.
एमएलए (9वां संस्करण) प्रशस्ति पत्रPitkin, Walter Boughton. The Art of Useful Writing. Whittlesey House, 1940.
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