Pravosudova, Elena V.; Grubb, Thomas C.; Parker, Patricia G.; Doherty, Paul F. (1999). "Patch Size and Composition of Social Groups in Wintering Tufted Titmice". The Auk. 116 (4): 1152–1155. doi:10.2307/4089699. JSTOR4089699.
Pravosudova, Elena V.; Grubb, Thomas C.; Parker, Patricia G.; Doherty, Paul F. (1999). "Patch Size and Composition of Social Groups in Wintering Tufted Titmice". The Auk. 116 (4): 1152–1155. doi:10.2307/4089699. JSTOR4089699.