RT Journal Article SR Electronic T1 β-Blockers for hypertension JF Canadian Medical Association Journal JO CMAJ FD Canadian Medical Association SP 971 OP 971 DO 10.1503/cmaj.1060198 VO 176 IS 7 A1 Hoffmann, Falk YR 2007 UL http://www.cmaj.ca/content/176/7/971.1.abstract