Spencer, L. M. (1993). Competence at Work (11th.). McGraw-Hill.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रSpencer, Lyle M. Competence at Work. 11th. Singapore: McGraw-Hill, 1993.
एमएलए (9वां संस्करण) प्रशस्ति पत्रSpencer, Lyle M. Competence at Work. 11th. McGraw-Hill, 1993.
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