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Sánchez-Arenas R, Rivera-García BE, Grijalva-Otero I, Juárez-Cedillo T, Toca-Porras L, Del Carmen Martínez-García M.Sánchez-Arenas R, et al.Cir Cir. 2009 Jan-Feb;77(1):13-9.Cir Cir. 2009.PMID: 19228465Spanish.