Internal Ophthalmoplegia, In Ocular Differential Diagnosis
Lea & Febiger, Phila. p 3375., Roy,F.H., 1975
Parkinson's Disease
In Handbk of Clinical Neurology, Vinken, P. J. & Bruyn, G. W. , Ed, North-Holland Publ Co, Amsterdam, 6:173, 1968. Selby, G., 1968