ČEH, Barbara, Robert HRASTAR, Anton TAJNŠEK, and Iztok Jože KOŠIR. 2008. “Impact of Source and Application Time of Sulphur on the Yield, Oil Content and Protein Content in Winter Oilseed Rape”. Acta Agriculturae Slovenica 91 (1): 5–14. https://doi.org/10.14720/aas.2008.91.1.15154.