Endoscope-assisted contralateral transmaxillary approach to the clivus and the hypoglossal canal: technical case report - Pamias-Portalatin, E; Mahato, D; Rincon-Torroella, J; Vivas-Buitrago, T; Quiñones-Hinojosa, A; Boahene, K O (J Neurosurg, 2018)