Cobaleda, G., Ehrlich, R. and Ferm, J. B. (1997) “Relationship between petrographic pore types and core measurements in sandstones of the Monserrate formation, upper Magdalena valley, Colombia”, CT&F - Ciencia, Tecnología y Futuro, 1(3), pp. 5–17. doi: 10.29047/01225383.585.