PT - JOURNAL ARTICLE ED - , TI - Prevalence of asthma among 12 year old children in New Zealand and South Wales: a comparative survey AID - 10.1136/thx.46.9.688-f DP - 1991 Sep 01 TA - Thorax PG - 688--688 VI - 46 IP - 9 4099 - http://thorax.bmj.com/content/46/9/688.7.short 4100 - http://thorax.bmj.com/content/46/9/688.7.full SO - Thorax1991 Sep 01; 46