First-night effects on subjective and objective measures of sleep in a large normative database. - Gruber,G.; Anderer,P.; Klösch,G.; Saletu,B.; Barbanoj,M-J.; Danker-Hopfe,H.; Himanen,S-L.; Kemp,B.; Penzel,T.; Röschke,J.; Dorffner,G. (J Sleep Res, 2000)