"Ip, Margaret" . "Wong, Alexandra" . "Tang, Julian" . "Hall, Stephen" . "16963681" . "PMC" . "Hui, David" . "2015-12-31"^^ . "16963681" . . "10.1378/chest.130.3.822" . . . "Chan, Matthew" . . . "no-cc" . "Airflows Around Oxygen Masks: A Potential Source of Infection" . . "PMC7094573" . "Chan, Paul" . "Chest" . "Sung, Joseph" . . .