Sandoval-Villa, Manuel. “Foliar Sprays of Calcium and Silicon on Incidence of Downy Mildew Disease in Lettuce”. REVISTA TERRA LATINOAMERICANA 24, no. 1 (March 1, 2006): 91. Accessed July 4, 2025. https://www.terralatinoamericana.org.mx/index.php/terra/article/view/1534.