RT Journal Article SR Electronic T1 Sputum IL-6 concentrations in severe asthma and its relationship with FEV1 JF Thorax JO Thorax FD BMJ Publishing Group Ltd and British Thoracic Society SP 537 OP 537 DO 10.1136/thx.2010.136523 VO 66 IS 6 A1 Morjaria, J B A1 Babu, K S A1 Vijayanand, P A1 Chauhan, A J A1 Davies, D E A1 Holgate, S T YR 2011 UL http://thorax.bmj.com/content/66/6/537.1.abstract AB