Zapf, H. Ecological thought and literature in Europe and Germany: Hubert Zapf. A Global History of Literature and the Environment.(2016).

Zapf, Hubert. "Ecological Thought and Literature in Europe and Germany: Hubert Zapf." A Global History of Literature and the Environment.(2016) .

Zapf, Hubert. "Ecological Thought and Literature in Europe and Germany: Hubert Zapf." A Global History of Literature and the Environment.(2016), .