[1]A. Krzemień и A. Dyszy, PMI, т. 170, вып. 2, сс. 200-202, апр. 2007.

[1]A. Krzemień and A. Dyszy, “Occupational health and safety management rules according to pier-merit program in polish coal mines”, PMI, vol. 170, no. 2, pp. 200-202, Apr. 2007.