@book{bhlitem23947, title = {Natur und Mensch }, copyright = {NOT_IN_COPYRIGHT}, url = {https://www.biodiversitylibrary.org/item/23947}, note = {https://www.biodiversitylibrary.org/bibliography/4782}, publisher = {Leipzig, Reclam, [pref. 1912]}, author = {Haeckel, Ernst, and Neumann, Carl W.}, year = {[pref. 1912]}, pages = {210}, }