Spaulding, Michelle; O'Leary, Maureen A.; Gatesy, John (2009). Farke, Andrew Allen (Ed.). "Relationships of Cetacea (Artiodactyla) Among Mammals: Increased Taxon Sampling Alters Interpretations of Key Fossils and Character Evolution". PLoS ONE. 4 (9). ss. e7062. doi:10.1371/journal.pone.0007062. PMC2740860 $2. PMID19774069.
Spaulding, Michelle; O'Leary, Maureen A.; Gatesy, John (2009). Farke, Andrew Allen (Ed.). "Relationships of Cetacea (Artiodactyla) Among Mammals: Increased Taxon Sampling Alters Interpretations of Key Fossils and Character Evolution". PLoS ONE. 4 (9). ss. e7062. doi:10.1371/journal.pone.0007062. PMC2740860 $2. PMID19774069.