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2. ASTM C 618-85: Standard Specification for “Fly Ash and Raw or Calcined Natural Pozzolan for Use as a Mineral Admixture in Portland Cement Concrete”. ASTM Satndars.
3. R. Talero: “Contribution to the Analytical and Physic-Chemical Study of the System: Pozzolanic Cements-Gypsum-Water (to 20 ° ± 3 °C)”. Doct. Thesis; Complut. Univ. of Madrid.