Transcranial DopplerStroke 19:915-921, DeWitt,L.D.&Wechsler,L.R., 1988
Evaluation of Cerebrovascular Disease by Combined Extracranial & Transcranial Doppler Sonography In 1, 039 PatientsStroke 18:1018-1024, Grolimund,P.,et al, 1987