Y. V. Arkhipov, A. B. Ashikbayeva, A. Askaruly, A. E. Davletov, D. Dubovtsev, and I. M. Tkachenko, “The loss function of dense plasmas and sum rules”, Int. j. math. phys., vol. 5, no. 1, pp. 53–59, Jun. 2014.