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pubmed.ncbi.nlm.nih.gov
Greenwold, M,; Sawyer, R, (2013), "Molecular evolution and expression of archosaurian β-keratins: Diversification and expansion of archosaurian β-keratins and the origin of feather β-keratins", Journal of Experimental Zoology, 320 (6): 393–405, doi:10.1002/jez.b.22514, PMID23744807, 22514CS1 maint: extra punctuation (link)