Wang P, Olsson BA, Lundkvist H 2007 Effects of wood ash, vitality fertilizer and logging residues on needle and root chemistry in a young Norway spruce stand Research article (Peer reviewed) DOI:10.1080/02827580701231480
Olsson BA, Kellner O 2006 Long-term effects of nitrogen fertilization on ground vegetation in coniferous forests Research article (Peer reviewed) DOI:10.1016/j.foreco.2006.09.068
Ring E, Bergholm J, Olsson BA, Jansson G 2003 Urea fertilizations of a Norway spruce stand: effects on nitrogen in soil water and field-layer vegetation after final felling Research article (Peer reviewed) DOI:10.1139/X02-187