Howard, E. W. (1969). Chemicals from nature. Published for the Nuffield Foundation by the Longmans/Penguin Books.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रHoward, E. W. Chemicals from Nature. London: Published for the Nuffield Foundation by the Longmans/Penguin Books, 1969.
एमएलए (9वां संस्करण) प्रशस्ति पत्रHoward, E. W. Chemicals from Nature. Published for the Nuffield Foundation by the Longmans/Penguin Books, 1969.
चेतावनी: ये उद्धरण हमेशा 100% सटीक नहीं हो सकते हैं.