// <I>NAA' 2012<D> : 5th International conference "Numerical analysis and Its applications'' 2012, Lozenetz, Bulgaria, 15-20 june 2012. - (Lect. notes in comp. sci., Springer, 8236, 2013, p. 206-213).
// <I>NODDEA' 2012<D> : International conference "Nonlinear difference and differential equations and their applications NODDEA" , Ruse, Bulgaria, october 3-6, 2012, p. 83-92.
// <I>AMEE 2017<D> : Proceedings of the 43rd International conference "Applications of mathematics in engineering and economics 2017", Sozopol, 8-13 june 2017, Ser. AIP conf. proc., 1910, 2017, Art. № 030008, DOI: 10.1063/1.5013967.