García de Paredes, P., J. Calleja, T. Vázquez, and J. L. Cebrián. “Investigation on the Meteorization of Cements by Infra-Red Spectroscopy”. Materiales De Construcción, vol. 19, no. 136, Dec. 1969, pp. 17-27, doi:10.3989/mc.1969.v19.i136.1574.