Ya. V. Lisitsyn, A. V. Shapovalov, “Noncommutative solutions of the d'Alembert equation”, Russ Phys J, 41:6 (1998), 528
Ya. V. Lisitsyn, A. V. Shapovalov, “Reduction of quantum analogs of Hamiltonian systems described by Lie algebras to orbits in a coadjoint representation”, Russ Phys J, 41:5 (1998), 460
A.V. Shapovalov, I.V. Shirokov, “Functional Algebras and Dimensional Reduction in the LPDEs Integration Problem”, JNMP, 4:1-2 (1997), 62
А. В. Шаповалов, И. В. Широков, “Метод некоммутативного интегрирования линейных дифференциальных уравнений. Функциональные алгебры и некоммутативная размерная редукция”, ТМФ, 106:1 (1996), 3–15 ; A. V. Shapovalov, I. V. Shirokov, “Noncommutative integration method for linear partial differential equations. Functional algebras and dimensional reduction”, Theoret. and Math. Phys., 106:1 (1996), 1–10
I. V. Shirokov, A. A. Drokin, “Quantum method of projection”, Russ Phys J, 39:9 (1996), 893