“Diet Composition of the Caspian Gull (Larus Cachinanns) in Inland Poland: Effects of Breeding Area, Breeding Stage and Sympatric Breeding With the Herring Gull (Larus Argentatus) ”. Ornis Fennica, vol. 88, no. 2, July 2011, pp. 80–89, https://doi.org/10.51812/of.133765.