Risk assessment of feasibility of roadheaders in Estonian underground miningSabanov, Sergei; Nikitin, Oleg; Pastarus, Jüri-RivaldoOil shale2008 / 2S, p. 153-162 : ill https://www.researchgate.net/publication/237790948_Risk_assessment_of_feasibility_of_roadheaders_in_Estonian_undergound_mining