00394nas a2200145   4500000000100000000000100001008004100002100001200043700001200055700001300067245011800080300001000198490000800208022003200216       1991                            d1 aH. Jick1 aS. Jick1 aL. Derby00aValidation of information recorded on general practitioner based computerised data resource in the United Kingdom  a766-80 v302  a0959-8138 (Print) 0959-8138