RT Journal Article SR Electronic T1 DIRECTORY OF POSTGRADUATE MEDICAL CENTRES JF The Journal of the Royal College of General Practitioners JO J R Coll Gen Pract FD British Journal of General Practice SP 311 OP 311 VO 28 IS 190 A1 D. J. Pereira Gray YR 1978 UL http://bjgp.org/content/28/190/311.2.abstract AB