Hernandez, Xenia E., Alejandro A. Orden, Oscar S. Giordano, and Marcela Kurina. 2005. “Effects of Elicitor and Copper Sulfate on Grindelic Acid Production in Submerged Cultures of Grindelia Pulchella”. Electronic Journal of Biotechnology 8 (3). Valparaíso, Chile:0-0. https://preprints.pucv.cl/index.php/ejbiotechnology/article/view/v8n3-6.