TY - GEN TY - GEN T1 - Rock drillability study T2 - Technical report / Helsinki University of Technology. Department of Minig and Metallurgy. Mining Engineering A1 - Salminen, Pekka, 1950- A2 - Viitala, Raimo, 1951- LA - eng PP - Otaniemi PB - Helsinki University of Technology YR - 1985 UL - https://kansalliskirjasto.finna.fi/Record/fikka.3355014 SN - 951-753-591-0 nidottu ER -