Лазаров, І. Г. “Formation and Analysis of the Varietal Structure of Tobacco (<i>Nicotiana tabacum</i≫ L.) and Tobacco Production in Bulgaria”. Plant Varieties Studying and Protection, vol. 13, no. 4, Dec. 2017, pp. 335-42, doi:10.21498/2518-1017.13.4.2017.117724.