@article{articlef09923b2,
title   = {Determination of in situ uniaxial compressive strength of coal seams based on geophysical data},
author = {Gonzatti, Clovis and Celestino, Tarcísio Barreto and Bortolucci, Antônio Airton},
year = {2009},
doi = {10.1007/s10064-008-0175-9},
journal   = {Bulletin of Engineering Geology and the Environment}
}