Leito, A., I. Ojaste, J. Truu, and A. Palo. “Nest Site Selection of the Eurasian Crane Grus Grus in Estonia: An Analysis of Nest Record Cards”. Ornis Fennica, vol. 82, no. 2, July 2005, pp. 44–54, https://ornisfennica.journal.fi/article/view/133632.