[1]J. Andrzejewska, The research of vertical displacements of the rock mass inside and in environment of the Kletno Bear Cave, PMI, т. 170, вып. 2, сс. 93-96, апр. 2007.

[1]J. Andrzejewska, PMI, vol. 170, no. 2, pp. 93-96, Apr. 2007.