Byrkjedal, I., K. Kyllingstad, S. Efteland, and S. Grøsfjell. “Population Trends of Northern Lapwing, Eurasian Curlew and Eurasian Oystercatcher over 15 Years in a Southwest Norwegian Farmland”. Ornis Norvegica, vol. 35, Feb. 2012, pp. 16-22, doi:10.15845/on.v35i0.238.