Ulett, Mark A. (2014). “Making the case for orthogenesis: The popularization of definitely directed evolution (1890–1926)”. Studies in History and Philosophy of Biological and Biomedical Sciences. 45: 124–132. doi:10.1016/j.shpsc.2013.11.009. PMID24368232.
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pubmed.ncbi.nlm.nih.gov
Ulett, Mark A. (2014). “Making the case for orthogenesis: The popularization of definitely directed evolution (1890–1926)”. Studies in History and Philosophy of Biological and Biomedical Sciences. 45: 124–132. doi:10.1016/j.shpsc.2013.11.009. PMID24368232.