4Aaslid R, Markwalder TM, Nomes H. Noninvasive transcranial Doppler Ultrasand,recording offow inbasal cerebral arteries. J Neurosurg, 1982, 57: 769- 774.
5Wong KS, Huang YN, Gao S. Intracranial stenosis in Chinese patients with acute stroke. Neurology, 1998 ,:50:812-813.
6Huang YN, Gao S, Li SW. Vascular Lesions in Chinese. patients with transient ischemic attacks. Neurology, 1997,48 : 524-525.
7Giovannoni G, Fritz VU. Transient ischemic Attacks in younger and older patients: a comparative study of 798 patients in South Africa. Stroke, 1993, 24: 947-953.
