The Spectrum of Neurol Dis Assoc with Antiphospholipid Antibd, Lupus Anticoag & Anticardiolipin AntibdArch Neurol 44:876-883, Levin,S.R.&Welch,K.M.A., 1987
The Natural History of SLE by Prospective AnalysisMedicine 50:85, Estes,D.,et al, 1971