Sahakyan, Albert Kh., and Rafayel R. Kamalian. “INTERVAL VERTEX-COLORINGS OF CACTUS GRAPHS WITH RESTRICTIONS ON VERTICES”. Proceedings of the YSU A: Physical and Mathematical Sciences, vol. 55, no. 3 (256), Nov. 2021, pp. 160-8, doi:10.46991/PYSU:A/2021.55.3.160.