Bedarev N.T., Lyubimov O.V., Sitnikov G.A., Kovalyov N.B. Strengthen monitoring of work roof bolting. Vestnik Kuzbasskogo gosudarstvennogo tekhnicheskogo universiteta=Bulletin of the Kuzbass State Technical University. 2012; 6(94):59-61. (In Russ., abstract in Eng.).