Krupa, M.; Ściborski, M.; Krupa, R.; Popis, R.; Wołoszyn, J. Differences in Foraging Ecology of Wood Sandpiper Tringa Glareola and Ruff Philomachus Pugnax During Spring Migration in Sajna River Valley (nor Thern Poland). Ornis Svec 2009, 19, 90-96.