[1]
Wiktander, U., Nilsson, I.N., Nilsson, S.G., Olsson, O., Pettersson, B. and Stagen, A. 1992. Occurrence of the Lesser Spotted Woodpecker Dendrocopos minor in relation to area of deciduous forest. Ornis Fennica. 69, 3 (Sep. 1992), 113–118.