Ángel Azañero Ortiz, V. Aramburú Rojas, L. Quiñones Lavado, L. Puente Santibañez, and P. Núñez Jara, “The problem of the natural activation of sphalerite during selective flotation”, Rev. Inst. investig. Fac. minas metal cienc. geogr, vol. 15, no. 29, pp. 83–90, Jul. 2012, doi: 10.15381/iigeo.v15i29.2207.