@article{article65cf5a2b,
title   = {Quality ranking of twelve columnar basalt occurrences in the northern portion of the Paraná basin - Brazil},
author = {Gomes, Ronaldo Lima and Rodrigues, José Eduardo},
year = {2007},
doi = {10.1016/j.enggeo.2007.02.004},
journal   = {Engineering Geology}
}