Authors: C A Wong; L J Walsh; C J Smith; A F Wisniewski; S A Lewis; R Hubbard; S Cawte; D J Green; M Pringle; A E Tattersfield Journal: Lancet Date: 2000-04-22 Impact factor: 79.321
Authors: R A Pauwels; C G Löfdahl; L A Laitinen; J P Schouten; D S Postma; N B Pride; S V Ohlsson Journal: N Engl J Med Date: 1999-06-24 Impact factor: 91.245