Vasileva, Elisaveta, et al. “ Extraction, Distribution and Efficiency of Nitrogen Use in Newly Created Genotypes of Common Winter Wheat (Triticum Aestivum)”. Bulgarian Journal of Crop Science, vol. 59, no. 5, Oct. 2022, pp. 21-27, https://agriacad.eu/ojs/index.php/bjcs/article/view/1810.