Cunningham, W. P. (1999). Environmental encyclopedia (2nd ed.). Gale, Jaico Publishing House.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रCunningham, William P. Environmental Encyclopedia. 2nd ed. Detroit : Mumbai: Gale, Jaico Publishing House, 1999.
एमएलए (8वां संस्करण) प्रशस्ति पत्रCunningham, William P. Environmental Encyclopedia. 2nd ed. Gale, Jaico Publishing House, 1999.
चेतावनी: ये उद्धरण हमेशा 100% सटीक नहीं हो सकते हैं.