Arkhipov, Y., A. Askaruly, V. Bychenkov, and I. Tkachenko. “THE OCP RELAXATION TIME: THE MOMENT METHOD VS. THE CORRECTED RPA”. Recent Contributions to Physics (Rec.Contr.Phys.), vol. 27, no. 3, Oct. 2008, pp. 8-11, https://bph.kaznu.kz/index.php/zhuzhu/article/view/1481.