OPEN UNIVERSITY. (1980). CASE STUDY STANDARD TELEPHONES AND CABLES. OPEN UNIVERSITY PRESS.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रOPEN UNIVERSITY. CASE STUDY STANDARD TELEPHONES AND CABLES. MILTON KEYNES: OPEN UNIVERSITY PRESS, 1980.
एमएलए (9वां संस्करण) प्रशस्ति पत्रOPEN UNIVERSITY. CASE STUDY STANDARD TELEPHONES AND CABLES. OPEN UNIVERSITY PRESS, 1980.
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