Zsombikné Puy, Katalin, Jánosné Borbély, and Zoltán Győri. “Results of a Fertilization Experiment Performed With Sulphur on Rape Seed Plants”. Acta Agraria Debreceniensis, no. 13 (May 4, 2004): 116–119. Accessed December 4, 2022. https://ojs.lib.unideb.hu/actaagrar/article/view/3394.