Calleja, J., F. Triviño, and B. Bacle. “Heterogeneities in the Chemical Composition of Concrete”. Materiales de Construcción 17, no. 127 (September 30, 1967): 33–51. Accessed April 28, 2024. https://materconstrucc.revistas.csic.es/index.php/materconstrucc/article/view/1653.