E. P. Mochalina
Plekhanov Russian University of Economics
Russian Federation

Ekaterina P. Mochalina, PhD, Associate Professor of the Department for Higher Mathematics 

36 Stremyanny Lane, Moscow, 109992

G. V. Ivankova
Plekhanov Russian University of Economics
Russian Federation

Galina V. Ivankova, Senior Lecture of the Department for Higher Mathematics 

36 Stremyanny Lane, Moscow, 109992

S. A. Smirnov
Saint-Petersburg State University; Durban University of Technology
Russian Federation

Sergey A. Smirnov, PhD, Associate Professor of the Department for Enterprise Economics and Entrepreneurship; Honorary Research Associate of the Department of Operations and Quality Management 

7/9 Universitetskaya Embankment, Saint Petersburg, 199034;
41 ML Sultan Road, Durban, South Africa.

Andrea Souza Santos
Federal University of Rio de Janeiro
Brazil

Andrea Souza Santos, D.Sc. COPPE 

2030 Horácio Macedo Avenue, Rio de Janeiro, 21941.