RT Journal Article SR Electronic T1 Standardization of the measurement of transfer factor: allowance for water vapour in the analysis of helium concentration JF European Respiratory Journal JO Eur Respir J FD European Respiratory Society SP 1814 OP 1814 DO 10.1183/09031936.95.08101814 VO 8 IS 10 A1 A Rizzo YR 1995 UL http://erj.ersjournals.com/content/8/10/1814.abstract AB