Stoyanova, Ts., Christov, O., Non-integrability of the Second Painleve equation as a Hamiltonian System, Compte Rendu de l'academie bulgare des sciences, vol. 60, 2007, p. 13-18.
Horozov, E., Stoyanova, Ts., Non-integrability of some Painleve VI-equations and dilogarithms, Regular and Chaotic Dynamics, vol. 12, 2007, p. 620-627.
Stoyanova, Ts,. Non-integrability of Painleve VI in the Liouville sense, Nonlinearity 22, 2009, p. 2201-2230.
Stoyanova, Ts., Non-integrability of Painleve V equations in the Liouville sense and Stokes phenomenon, Advances in Pure Mathematics, vol.1, n.4, July 2011, pp. 170-183.
Tsvetana Stoyanova, Non-integrability of thr fourth Painleve equation in the Liouville-Arnold sense, Nonlinearity 27 (2014), pp.1029-1044.
Tsvetana Stoyanova, Zero level perturbation of a certain third-order linear ODE with an irregular singularity at the origin of Poincare rank 1, J. Dyn. Control Syst. 24, No. 4, 2018, pp. 511-539.
Tsvetana Stoyanova, Stokes matrices of a reducible double confluent heun equation via monodromy matrices of a reducible general Heun equation with symmetric finite singularities, J. Dyn. Control Syst. 28, N0. 1, 2022, pp. 247-248.
Tsvetana Stoyanova, Nonintegrability of the Painleve IV equation in the Liouville-Arnold sense and Stokes phenomena, Studies in Applied Mathematics, 2023.