Nilsson, Jan-Eric. “A 20-Year Study of a Nest-Box Breeding Bird Population With Special Regard to the Pied Flycatcher Ficedula Hypoleuca”. Ornis Svecica 18, no. 1 (October 31, 2019): 52–64. Accessed November 22, 2024. https://journals.lub.lu.se/os/article/view/20235.