Halanay, Andrei, <span style="color: #000000;">Department of Mathematics and Informatics, University </span><span style="text-decoration: underline; color: #000000;">Politehnica</span><span style="color: #000000;"> of Bucharest,</span><span style="color: #000000;"> 313 </
Hommel, Angela HORAK, VLADIMIR, UNIVERSITY OF DEFENCE, BRNO
Horak, Vladimir, <p>University of Defence</p>