Veistola, S., Lehikoinen, E. and Eeva, T. 1997. Foraging niches of two passerines at their subarctic limit of distribution: the Siberian Tit Parus cinctus and the Pied Flycatcher Ficedula hypoleuca. Ornis Fennica. 74, 2 (Jul. 1997), 79–87.