BibTex format
@article{Passas:1996,
author = {Passas, N and Butenuth, C and de, Freitas MH},
journal = {Bulletin of the Association of Engineering Geology},
pages = {83--95},
title = {A non-volumetric method of measuring the ratio of solid and voids in porous material with a computer aided system},
volume = {53},
year = {1996}
}