Kennedy, Martyn; Spencer, Hamish G (2004). «Phylogenies of the frigatebirds (Fregatidae) and tropicbirds (Phaethonidae), two divergent groups of the traditional order Pelecaniformes, inferred from mitochondrial DNA sequences». Molecular Phylogenetics and Evolution31 (1): 31-38. ISSN1055-7903. PMID15019606. doi:10.1016/j.ympev.2003.07.007.
Kennedy, Martyn; Spencer, Hamish G (2004). «Phylogenies of the frigatebirds (Fregatidae) and tropicbirds (Phaethonidae), two divergent groups of the traditional order Pelecaniformes, inferred from mitochondrial DNA sequences». Molecular Phylogenetics and Evolution31 (1): 31-38. ISSN1055-7903. PMID15019606. doi:10.1016/j.ympev.2003.07.007.
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Kennedy, Martyn; Spencer, Hamish G (2004). «Phylogenies of the frigatebirds (Fregatidae) and tropicbirds (Phaethonidae), two divergent groups of the traditional order Pelecaniformes, inferred from mitochondrial DNA sequences». Molecular Phylogenetics and Evolution31 (1): 31-38. ISSN1055-7903. PMID15019606. doi:10.1016/j.ympev.2003.07.007.