Founded in 1961, the Sleep Research Society (SRS) has been gathering experts together for half a century to explore the mysteries and possibilities of the human sleep cycle. This page features a dozen historically significant papers on the nature of sleep, from E. Pfluger's 1686 paper (in German) on Dyspnea and Apnea to four groundbreaking 20th century papers by A.R. Morrison and O. Pompeiano. Readers may simply select any title to view or download the paper in full. For readers fascinated by the complexities of sleep, and for those who love to go back to original source material, this site from the SRS is a virtual treasure trove of free knowledge.