Zapf, H. Ecological thought and literature in Europe and Germany: Hubert Zapf. A Global History of Literature and the Environment.(2016).
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रZapf, Hubert. "Ecological Thought and Literature in Europe and Germany: Hubert Zapf." A Global History of Literature and the Environment.(2016) .
एमएलए (8वां संस्करण) प्रशस्ति पत्रZapf, Hubert. "Ecological Thought and Literature in Europe and Germany: Hubert Zapf." A Global History of Literature and the Environment.(2016), .
चेतावनी: ये उद्धरण हमेशा 100% सटीक नहीं हो सकते हैं.