Source: http://www.stanfordchildrens.org/en/topic/default%3Fid%3Dnewborn-sleep-patterns-90-P02632&sa=U&ei=58e3VM6CIIr5yATNnIGwAg&ved=0CG8QFjAT&usg=AFQjCNFvyKhlh5_8yFZvCBirEv-fTY56pQ