Rasulov, T. and Khudayarov, S. (2019) “ON THE SPECTRUM OF A FIRST SCHUR COMPLEMENT RELATED WITH A 3X3 OPERATOR MATRIX”, Journal of Global Research in Mathematical Archives(JGRMA), 6(10), pp. 13–16. Available at: https://jgrma.com/index.php/jgrma/article/view/550 (Accessed: 14 March 2025).