%0 Generic %D 1998 %T Differential effects of ammonium nitrate on three heathland species %A De Graaf, M.C.C. %A Bobbink, R. %A Roelofs, J.G.M. %A Verbank, P.J.M. %B Plant Ecology %V 135 %P 185-196 %0 Generic %D 1993 %T Distribution and decline of endangered herbaceous heathland species in relation to the chemical composition of the soil %A Houdijk, A.L.F.M. %A Verbank, P.J.M. %A van Dijk, H.F.G. %A Roelofs, J.G.M. %B Plant and Soil %V 148 %P 137-143 %G eng