title: Secretion clearance techniques: absence of proof or proof of absence?
authors.forename: Dean R
authors.initials: DR
authors.lastname: Hess
mesh_terms: D002986:Clinical Trials as Topic; D006801:Humans; D008168:Lung / Q000378:metabolism*; D009079:Mucociliary Clearance; D012107:Research Design; D012138:Respiratory Therapy