RT Journal Article SR Electronic T1 The need for biomarkers in amyotrophic lateral sclerosis drug development JF Neurology JO Neurology FD Lippincott Williams & Wilkins SP 11 OP 12 DO 10.1212/01.wnl.0000338538.18938.9d VO 72 IS 1 A1 Wagner, Kathryn R. YR 2009 UL http://n.neurology.org/content/72/1/11.abstract AB