Viral Infections of the Nervous System, Chronic Meningitis, and Prior Diseases, Acute Anterior Poliomyelitis
Adams & Victors Principles of Neurology, Chp 33, pg 763, Ropper, A.H.,et al, 2014
Diagnosis and Management of Motor Neurone Disease
BMJ 336:658-662, McDermott,C.J. &Shaw,P.J., 2008