Pankov A.

Nonlinear Analysis: Real World Applications. Vol. 50. 2019. P.. 603-612

Nonlinear Analysis, Theory, Methods and Applications. Vol. 184. 2019. P.. 258-272

Advances in Nonlinear Analysis. Vol. 8. 2019. P.. 372-385

Discrete and Continuous Dynamical Systems- Series A. Vol. 38. 2018. P.. 697-714