American Association of Medical Chronobiology and Chronotherapeutics
   Provides an organizational framework for medical scientists, including academic and practicing physicians, interested in chronobiological phenomena.
   http://www.aamcc.net

American Society for Gravitational and Space Biology -- Desert Beetle Circadian Rhythm Study Begins on Mir
   When Space Shuttle Atlantis docked with Mir on May 15, it delivered 64 desert beetles for a circadian rhythm study to understand how the space flight environment changes the body's internal clock.
   http://asgsb.indstate.edu/newsletter/v13_2/beetle.html

Circadian Sleep Disorders Association
   Support and providing information to those affected by circadian sleep disorders such as Delayed Sleep Phase Syndrome. Includes links, FAQs, message board and a mailing list.
   http://www.circadiandisorders.org/

Light Sets the Molecular Controls of Circadian Rhythm
   Work conducted at the Rockefeller University indicates that light can reset the biological clock.
   http://www.rockefeller.edu/pubinfo/light.nr.html

Mental Health Net - Circadian Rhythm Sleep Disorder Symptoms
   General symptoms of circadian rhythm sleep disorder.
   http://mentalhelp.net/disorders/sx92.htm

Scientists Find Eye Pigment Controls Circadian Rhythm
   A brief report on an eye pigment, cryptochrome, which appears to control mammals' circadian rhythms.
   http://www.eurekalert.org/pub_releases/1998-11/UoNC-DECN-191198.php

Society for Light Treatment and Biological Rhythms
   A not-for-profit international organization founded in 1988 which aims to foster research, professional development and clinical applications in the fields of light therapy and biological rhythms.
   http://www.websciences.org/sltbr/

The Brain, Circadian Rhythms, and Clock Genes
   British Medical Journal Article on circadian rhythms (1998). A clinical review.
   http://www.bmj.com/cgi/content/full/317/7174/1704