Paroxysmal Tonic Upgaze:a Reappraisal of OutcomeAnn Neurol 43:514-520, Hayman,M.,et al, 1998
The Ocular Manifestations of Multiple Sclerosis, 2, Abnormalities of Eye MovementsJNNP 55:863-868, Barnes,D.&McDonald,W.I., 1992