Zsombikné Puy, Katalin, Jánosné Borbély, and Zoltán Győri. 2004. “Results of a Fertilization Experiment Performed With Sulphur on Rape Seed Plants”. Acta Agraria Debreceniensis, no. 13 (May): 116-19. https://doi.org/10.34101/actaagrar/13/3394.