Zigmontienė, Aušra, and Indrė Liberytė. 2014. “Changes in the Concentration of Heavy Metals (Cr, Cd, Ni) During the Vermicomposting Process of Sewage Sludge”. Mokslas – Lietuvos Ateitis / Science – Future of Lithuania 6 (4):362-67. https://doi.org/10.3846/mla.2014.49.