[1]https://www.nimh./health/topics/seasonal-affective-disorder/index.shtml
[2]https://www./us/conditions/seasonal-affective-disorder
[3]https://www./us/blog/the-antidepressant-diet/201109/hibernate-cookies-and-improve-the-symptoms-seasonal-affective
[4]https://www./us/blog/natural-standard/201201/feeling-sad-season