<h1>&nbsp;</h1> <div class="toc-about clearfix"> <h1><a href="http://many.at/links2tabs" class="header">Psychology - психологія 心理学 psychologie 心理學 ψυχολογία psychologia मनोविज्ञान pszichológia உளவியலாளர்கள் psicologia మానసిక నిపుణులు 심리학 psykologi tâm lý học psikoloji психология psicólogos علم النفس psicología פסיכולוגיה</a></h1><p>References 1 - 4 for Is Weekend &#039;Social Jet Lag&#039; Harming Your Health?</p> </div><!-- class="about clearfix" --><h1>&nbsp;</h1> <div id="mysitesnoframes" class="sites_content"><ul> <li><a rel="nofollow" href="http://www.health.com/health/" ><img src="/wp-content/images/icons/32/globe2.png" width="32" height="32" /><strong>[1] Reference</strong>health.com</a></li> <li><a rel="nofollow" href="http://www.health.com/health/gallery/0,,20506099,00.html" ><img src="/wp-content/images/icons/32/globe3.png" width="32" height="32" /><strong>[2] 10 Alarm Clocks for Heavy Sleepers</strong>health.com</a></li> <li><a rel="nofollow" href="http://www.health.com/health/gallery/0,,20459221,00.html" ><img src="/wp-content/images/icons/32/globe4.png" width="32" height="32" /><strong>[3] Surprising Health Benefits of Sleep</strong>health.com</a></li> <li><a rel="nofollow" href="http://www.health.com/health/gallery/0,,20445804,00.html" ><img src="/wp-content/images/icons/32/globe5.png" width="32" height="32" /><strong>[4] How Much Sleep Do You Really Need?</strong>health.com</a></li> </ul></div> Your browser does not handle frames, which are required to view the sites in tabs. Please upgrade to a more modern browser.<br /><br />