The interplay of two significant processes regulates the sleep-wake system.<ref>Gillette M, Abbott S. Sleep Research Society. SRS Basics of Sleep Guide. Westchester, IL: Sleep Research Society; 2005. Fundamentals of the circadian system; pp. 131–138.</ref> | The interplay of two significant processes regulates the sleep-wake system.<ref>Gillette M, Abbott S. Sleep Research Society. SRS Basics of Sleep Guide. Westchester, IL: Sleep Research Society; 2005. Fundamentals of the circadian system; pp. 131–138.</ref> |