2×2 operator matrix with real parameter and its spectrumElyor B. Dilmurodov, Nargiza A. Tosheva, Nabiya A. Turayeva, Bolatbek T. Karamatov and Durdona Sh. ShokirovaE3S Web Conf., 587 (2024) 03002DOI: https://doi.org/10.1051/e3sconf/202458703002