“Synthesis Of Pharmacologically Active Hexahydroacridine-1,8 (2H, 5H)-Diones Using Nickel (II) Flouride Tetrahydrate As a New Heterogeneous Catalyst”. Communication In Physical Sciences, vol. 5, no. 2, Apr. 2020, pp. 83-98, https://journalcps.com/index.php/volumes/article/view/348.