Conde Suárez, P., S. Seoane, E. López Mosquera, F. Solla Gullón, and A. Merino. “Dairy Industry Sewage Sludge As a Fertilizer for an Acid Soil: A Laboratory Experiment With Lolium Multiflorum L.”. Spanish Journal of Agricultural Research, Vol. 2, no. 3, Sept. 2004, pp. 419-27, doi:10.5424/sjar/2004023-97.