1. Babushkina, O.V. and Bojarinova, Yu.G., Maintenance of Family Connections in Migrating Long-Tailed Tits, Aegithalos c. caudatus: The Ringing Data from Northwest Russia, Vestn. St.-Peterb. Gos. Univ., Ser. Biol., 2009, no. 2, pp. 3–11.
2. Bardin, A.V. and Rezvyi, S.P., Invasions in Birds: Two Approaches to the Problem, XII Pribalt. ornitol. konf.: Tez.dokl. (Abstr. XII Baltic Ornithol. Conf.), Vilnius, 1988, pp. 13–14.
3. Bensch, S. and Nielsen, B., Autumn Migration Speed of Juvenile Reed and Sedge Warblers in Relation to Date and Fat Loads, Condor, 1999, vol. 101, pp. 153–156.
4. Blumenthal, T.I. and Dolnik, V.R., Evaluation of Energy Parameters of Birds in the Field, Ornitologiya, 1962, no. 4, pp. 394–407.
5. Bojarinova, J., Ilves, A., Chernetsov, N., and Leivits, A., Body Mass, Moult and Migration Speed of the Goldcrest Regulus regulus in Relation to the Timing of Migration at Different Sites of the Migration Route, Ornis Fenn., 2008, vol. 85, no. 2, pp. 55–65.