TY - JOUR PB - American Physical Society ID - 10.1103/PhysRevFocus.21.1 TI - Why Sleep? JF - Physical Review Focus JA - Phys. Rev. Focus J1 - FOCUS VL - 21 IS - SP - 1 EP - PY - 2008/01/08/ UR - http://link.aps.org/doi/10.1103/PhysRevFocus.21.1 A1 - Schirber, Michael ER -