Dimitrova, N. G., and L. Nacheva. “Micropropagation of Helichrysum Italicum (ROTH) G. Don – a Medicinal Plant With Ornamental Value”. Journal of BioScience and Biotechnology, vol. 7, no. 2-3, Feb. 2019, pp. 97-101, https://editorial.uni-plovdiv.bg/index.php/JBB/article/view/164.