Independent analysts and forecasters. (2017). Oil World. ISTA Mielke GmbH.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रIndependent analysts and forecasters. Oil World. Hamburg, Alemanha: ISTA Mielke GmbH, 2017.
एमएलए (8वां संस्करण) प्रशस्ति पत्रIndependent analysts and forecasters. Oil World. ISTA Mielke GmbH, 2017.
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