Holovatiuk, V. M., Y. V. Bezugly, and V. I. Kashkovsky. “Synthesis of New 4,4-Spirocycloalkenic 1,2-Diphenylpyrazolidine-3,5-Dione Derivatives by Ring-Closing Metathesis Reactions”. Journal of Organic and Pharmaceutical Chemistry, vol. 12, no. 3(47), Sept. 2014, pp. 33-37, doi:10.24959/ophcj.14.803.