„GROUPS OF OPERATORS IN C2 DETERMINED BY SOME COSINE OPERATOR FUNCTIONS IN C2“, bjami, Bd. 3, Nr. 1, S. pp. 63–72, Juni 2020, Zugegriffen: 3. Oktober 2025. [Online]. Verfügbar unter: https://js.ugd.edu.mk/index.php/bjami/article/view/3517