Bukaciński, D., Bukacińska, M. and Buczyński, A. 2018. Threats and the active protection of birds in a riverbed: postulates for the strategy of the preservation of the middle Vistula River avifauna. Studia Ecologiae et Bioethicae. 16, 4 (Dec. 2018), 5–23. DOI:https://doi.org/10.21697/seb.2018.16.4.01.