Sergio Vázquez, María José Villanueva, José Luis Fírvida, Begoña Campos, Martín Lázaro, Gerardo Huidobro, María del Carmen Areses, Natalia Fernández, Marta Covela, and Joaquín Casal. “Erlotinib As Second-Line Therapy for Patients With Advanced Non-Small-Cell Lung Cancer and Wild-Type EGFR Tumors”. Journal of Analytical Oncology 4, no. 3 (June 20, 2015):  94–101. Accessed December 2, 2023. https://www.neoplasiaresearch.com/pms/index.php/jao/article/view/250.