Rasulov, T. and Tosheva, N. (2019) “NEW BRANCHES OF THE ESSENTIAL SPECTRUM OF A FAMILY OF 3x3 OPERATOR MATRICES”, Journal of Global Research in Mathematical Archives(JGRMA), 6(9), pp. 18–21. Available at: https://jgrma.com/index.php/jgrma/article/view/543 (Accessed: 14 March 2025).