RT Journal Article SR Electronic T1 Long-term β interferon in MS: safe, but what effect on disability? JF Journal of Neurology, Neurosurgery & Psychiatry JO J Neurol Neurosurg Psychiatry FD BMJ Publishing Group Ltd SP 825 OP 826 DO 10.1136/jnnp.2010.208017 VO 81 IS 8 A1 Neil J Scolding YR 2010 UL http://jnnp.bmj.com/content/81/8/825.abstract AB