Porter, M. E. (1998). On competition. Harvard Businesss School Publishing.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रPorter, Michael E. On Competition. Boston: Harvard Businesss School Publishing, 1998.
एमएलए (9वां संस्करण) प्रशस्ति पत्रPorter, Michael E. On Competition. Harvard Businesss School Publishing, 1998.
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