Castellote, M., M. C. Alonso, and C. Andrade. “Determination of the OH- Content in the Aqueous Phase of Hardened Cementitious Materials by an Empirical Leaching Method”. Materiales De Construcción, vol. 52, no. 265, Mar. 2002, pp. 39-56, doi:10.3989/mc.2002.v52.i265.343.