RT Journal Article SR Electronic T1 CHEWING GUM PROPHYLAXIS JF The Journal of the Royal College of General Practitioners JO J R Coll Gen Pract FD British Journal of General Practice SP 405 OP 405 VO 22 IS 119 A1 Godfrey Ripley YR 1972 UL http://bjgp.org/content/22/119/405.2.abstract AB