Podgaiskytė, V., and P. Vaitiekūnas. “Determination of Cadmium in a Municipal Sewage Sludge Based Compost by Spectrophotometric Method”. Journal of Environmental Engineering and Landscape Management, vol. 17, no. 4, Dec. 2009, pp. 219-25, doi:10.3846/1648-6897.2009.17.219-225.