RT Journal Article SR Electronic T1 Oral contraceptives and hypertension. An epidemiological survey. JF British Heart Journal JO Heart FD BMJ Publishing Group Ltd and British Cardiovascular Society SP 1238 OP 1243 DO 10.1136/hrt.34.12.1238 VO 34 IS 12 A1 T M Clezy A1 B N Foy A1 R L Hodge A1 E R Lumbers YR 1972 UL http://heart.bmj.com/content/34/12/1238.abstract AB