Philippines. Bureau of Posts. Planning Division. (1976). Systems study: Postal operations. The Bureau.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रPhilippines. Bureau of Posts. Planning Division. Systems Study: Postal Operations. [Manila]: The Bureau, 1976.
एमएलए (9वां संस्करण) प्रशस्ति पत्रPhilippines. Bureau of Posts. Planning Division. Systems Study: Postal Operations. The Bureau, 1976.
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