Petrov, N. M. “Antiviral Activity оf Plant Extract From Tanacetum Vulgare Against Cucumber Mosaic Virus And Potato Virus Y”. Journal of BioScience and Biotechnology, vol. 5, no. 2, Sept. 2016, pp. 189-94, https://editorial.uni-plovdiv.bg/index.php/JBB/article/view/34.