Cioban M, Cozma D, Dohotaru L. International Symposium "Actual Problems of Mathematics and Informatics" dedicated to the 90th birthday of professor Ion Valutse. ActaEX [Internet]. 2021Jan.12 [cited 2024Oct.16];10(2):117–124. Available from: https://revistaust.upsc.md/index.php/acta_exacte/article/view/601