Hagen, Joel B. (1984-01-01). "Experimentalists and Naturalists in Twentieth-Century Botany: Experimental Taxonomy, 1920-1950". Journal of the History of Biology. 17 (2): 249–270. doi:10.1007/bf00143734. JSTOR4330893. S2CID83892384.
Kupper, Patrick (2009-01-01). "Science and the National Parks: A Transatlantic Perspective on the Interwar Years". Environmental History. 14 (1): 58–81. doi:10.1093/envhis/14.1.58. JSTOR25473328.
Hagen, Joel B. (1984-01-01). "Experimentalists and Naturalists in Twentieth-Century Botany: Experimental Taxonomy, 1920-1950". Journal of the History of Biology. 17 (2): 249–270. doi:10.1007/bf00143734. JSTOR4330893. S2CID83892384.
Kupper, Patrick (2009-01-01). "Science and the National Parks: A Transatlantic Perspective on the Interwar Years". Environmental History. 14 (1): 58–81. doi:10.1093/envhis/14.1.58. JSTOR25473328.
Hagen, Joel B. (1984-01-01). "Experimentalists and Naturalists in Twentieth-Century Botany: Experimental Taxonomy, 1920-1950". Journal of the History of Biology. 17 (2): 249–270. doi:10.1007/bf00143734. JSTOR4330893. S2CID83892384.