@article {702, title = {Thinner eggshells of dipper (Cinclus cinclus) eggs from an acidified area compared to a non-acidified area in Norway}, journal = {Water, Air and Soil Pollution}, volume = {93}, year = {1997}, pages = {255-266}, author = {Nybx, S. and Staurnes, M. and Erstad, K.J.} } @article {474, title = {Nutrient balance in Scots Pine Forest I: Design of experiments}, journal = {Water, Air and Soil Pollution}, volume = {85}, year = {1995}, pages = {1125-1130}, author = {Abrahamsen, G. and Erstad, K.J.} }