Kovalchuk, G., A. Fernández-Jiménez, and A. Palomo. “Alkali-Activated Fly Ash. Relationship Between Mechanical Strength Gains and Initial Ash Chemistry”. Materiales De Construcción, vol. 58, no. 291, Sept. 2008, pp. 35-52, doi:10.3989/mc.2008.v58.i291.101.