V. E. Sidorovich, D. I. Shamovich, I. A. Solovey, and G. O. Lauzhel, “Dietary variations of the Ural Owl Strix uralensis in the transitional mixed forest of northern Belarus with implications for the distribution differences”, Ornis Fenn, vol. 80, no. 4, pp. 145–158, Dec. 2003.