RT Journal Article SR Electronic T1 Some features of screening programmes. JF British Journal of Preventive & Social Medicine JO Br J Prev Soc Med FD BMJ Publishing Group Ltd SP 63 DO 10.1136/jech.27.1.63 VO 27 IS 1 A1 M J Gardner YR 1973 UL http://jech.bmj.com/content/27/1/63.1.abstract AB