Puhakainen, M., and T. Yläranta. “Uptake of Radionuclides by Spring Wheat and Barley from Cultivated Soils Supplemented by Contaminated Sewage Sludge”. Agricultural and Food Science, vol. 1, no. 1, Jan. 1992, pp. 27-36, doi:10.23986/afsci.72427.