Critical evaluation of screening questionnaires for obstructive sleep apnea in patients undergoing coronary artery bypass grafting and abdominal surgery - Nunes, Flavia S.; Danzi-Soares, Naury J.; Genta, Pedro R.; Drager, Luciano F.; Cesar, Luiz A. M.; Lorenzi-Filho, Geraldo (Sleep and Breathing, 2015)