1Leksell D. Letters to the editor. Stereotactic surgery:open or closed?[J]. J Neurosurg,1991, 74(5) :855.
2Pernercky A, Muller-Forell W, Lindert VE,et al. Keyhole concept in neurosurgery. With endoscope-assisted microsurgery and case studies[M]. Stuttgart: Thieme, 1999. 56.