“The Complete Integrability and Picard - Fuchs Equations of a Four-Dimensional Truncated Focker-Plank Hamiltonian System. I”. Neliniini Kolyvannya, vol. 4, no. 2, June 2001, pp. 264-71, https://twinhead.imath.kiev.ua/index.php/nosc/article/view/170.