Characterisation of distal bronchial microflora during acute exacerbation of chronic bronchitis. Use of the protected specimen brush technique in 54 mechanically ventilated patients - Fagon,J.Y.; Chastre,J.; Trouillet,J.L.; Domart,Y.; Dombret,M.C.; Bornet,M.; Gibert,C. (Am Rev Respir Dis, 1990)