RT Journal Article SR Electronic T1 Essential tremor, beta-blockers, and calcium channel blockers (December 2011) JF Cleveland Clinic Journal of Medicine JO Cleve Clin J Med FD Cleveland Clinic SP 242 OP 242 DO 10.3949/ccjm.79c:04004 VO 79 IS 4 A1 Keller, David L. YR 2012 UL http://www.ccjm.org/content/79/4/242.1.abstract AB