Singh, A. K. (1981). Patterns of regional development: A comparative study. Sterling Pubs. Pvt. Ltd.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रSingh, Ajit Kumar. Patterns of Regional Development: A Comparative Study. Sterling Pubs. Pvt. Ltd, 1981.
एमएलए (9वां संस्करण) प्रशस्ति पत्रSingh, Ajit Kumar. Patterns of Regional Development: A Comparative Study. Sterling Pubs. Pvt. Ltd, 1981.
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