Howard, K. S. (1967). The enjoyment of chess problems (4th ed.). Dover.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रHoward, Kenneth Samuel. The Enjoyment of Chess Problems. 4th ed. New York: Dover, 1967.
एमएलए (9वां संस्करण) प्रशस्ति पत्रHoward, Kenneth Samuel. The Enjoyment of Chess Problems. 4th ed. Dover, 1967.
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