Gill, F. B.; Slikas, B.; Sheldon, F. H. (2005). "Phylogeny of Titmice (Paridae): Ii. Species Relationships Based on Sequences of the Mitochondrial Cytochrome-B Gene". The Auk. 122: 121. doi:10.1642/0004-8038(2005)122[0121:POTPIS]2.0.CO;2. S2CID86067032.
Gill, F. B.; Slikas, B.; Sheldon, F. H. (2005). "Phylogeny of Titmice (Paridae): Ii. Species Relationships Based on Sequences of the Mitochondrial Cytochrome-B Gene". The Auk. 122: 121. doi:10.1642/0004-8038(2005)122[0121:POTPIS]2.0.CO;2. S2CID86067032.