000 00270 a2200109 4500
005 20220505024723.0
022 _a0143005X
245 _aJournal of Epidemiology and community Health
260 _aLondon,
_bBritish Medical Journal:
_c1984.
490 _v30
942 _2lcc
_cCR
999 _c21368
_d21368