Panayotova, G. ., S. . Kostadinova, and I. . Velinov. “ENERGY EFFICIENCY OF NITROGEN FERTILIZATION IN DURUM WHEAT AND SORGHUM GRAINS”. Proceedings of CBU in Natural Sciences and ICT, vol. 1, Nov. 2020, pp. 78-84, doi:10.12955/pns.v1.126.