Berg, Jeremy M., et al. “Evolution Requires Reproduction, Variation, and Selective Pressure.” Biochemistry. 5th Edition., W H Freeman, 2002, https://www.ncbi.nlm.nih.gov/books/NBK22508/.
Kutschera, Ulrich, and Karl J. Niklas. “The Modern Theory of Biological Evolution: An Expanded Synthesis.” Naturwissenschaften, vol. 91, no. 6, 2004, pp. 255–76, doi:10.1007/s00114-004-0515-y.
Penny, David. “Darwin’s Theory of Descent with Modification, versus the Biblical Tree of Life.” PLoS Biology, vol. 9, no. 7, Public Library of Science, July 2011, pp. 1–4, doi:10.1371/journal.pbio.1001096.
Biointeractive Finch resource: