1. N. P. Bazhin et al., Maintenance of Development Workings without Pillars [in Russian], Moscow (1975).
2. N. M. Dvoretskii and I. D. Cherepanov, “Exploitation of mechanized systems without leaving protective pillars of coal,” in: Technology of Underground Coal Winning [in Russian], Nos. 11, 12 (1970).
3. M. P. Popkov, “Working of extraction sections with simultaneous liquidation of interface pillars,” in: Technology of Underground Coal Winning [in Russian], No. 6 (1972).
4. Shpil'ko and G. A. Tolstykh, “Mechanized working of safety pillars in the Polysaevskaya Mine of the Kuzbassugol' Combine,” in: Technology of Underground Coal Winning [in Russian], No. 8 (1973).
5. K. A. Ardashev and N. P. Bazhin, “Geomechanical principles of choice and perfection of pillarless methods of protection and maintenance of development workings,” Ugol', No. 9 (1976).