Authors
Tamara Grizane
Institute of Energy Systems and Environment, Riga Technical University, Riga, Latvia
Inguna Jurgelane-Kaldava
International Business and Customs Institute, Riga Technical University, Riga, Latvia
© 2019 Tamara Grizane, Inguna Jurgelane-Kaldava, published by Riga Technical University
This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.