Lazdiņa, D., Lazdiņš, A., Kariņš, Z. and Kāposts, V. 2007. Effect of sewage sludge fertilization in short‐rotation willow plantations. Journal of Environmental Engineering and Landscape Management. 15, 2 (Jun. 2007), 105-111. DOI:https://doi.org/10.3846/16486897.2007.9636916.