RT Journal Article SR Electronic T1 Marriage and risk of dementia: systematic review and meta-analysis of observational studies JF Journal of Neurology, Neurosurgery & Psychiatry JO J Neurol Neurosurg Psychiatry FD BMJ Publishing Group Ltd SP 227 OP 227 DO 10.1136/jnnp-2017-317178 VO 89 IS 3 A1 Chen, Christopher P L H A1 Mok, Vincent C T YR 2018 UL http://jnnp.bmj.com/content/89/3/227.abstract AB