1.) Evaporative water loss and sleep stages in patients with obstruktive sleep apnea Somnologie 1997; 1: 16 Randerath W., Ströhlein G., Ryba J. Rühle K.H.
2.) Comparison of Diaphragmatic EMG and Oesophageal Pressure in Obstructed and Unobstructed Breathing during Sleep - Lennart Knaack, Hans-Christian Blum, Winfried Hohenhorst, Jan Ryba, Christian Guilleminault, Riccardo A. Stoohs. Somnologie: 9: 159-165, 2005