“SYNTHESIS OF 7-HYDROXY-2,8-DIMETHYL-4-OXO-3-PHENOXY-4H-6-CHROMENECARBALDEHYDE: DOI: Https: doi.Org 10.17721 1728-2209.2018.1(55).13”. 2019. Bulletin of the Taras Shevchenko National University of Kyiv. Chemistry 55 (1): 54-57. https://chemistry.bulletin.knu.ua/article/view/8392.