RT Journal Article SR Electronic T1 Velcro crackles: the key for early diagnosis of idiopathic pulmonary fibrosis? JF European Respiratory Journal JO Eur Respir J FD European Respiratory Society SP 519 OP 521 DO 10.1183/09031936.00001612 VO 40 IS 3 A1 Vincent Cottin A1 Jean-François Cordier YR 2012 UL http://erj.ersjournals.com/content/40/3/519.abstract AB