RT Journal Article SR Electronic T1 THIRD INTERNATIONAL CONGRESS ON GROUP MEDICINE JF The Journal of the Royal College of General Practitioners JO J R Coll Gen Pract FD British Journal of General Practice SP 839 OP 840 VO 25 IS 160 A1 John Marks YR 1975 UL http://bjgp.org/content/25/160/839.3.abstract AB