Fondell E, Lagerros YT, Sundberg CJ, Lekander M, Balter O, Rothman KJ, Balter K. Physical activity, stress, and self-reported upper respiratory tract infection. Med Sci Sports Exerc. 2011 Feb 1;43(2):272-9.
Johannes CB, Crawford SL. Menstrual bleeding, hormones, and the menopausal transition. Semin Reprod Endocrinol. 1999 Jan 1;17(4):299-309.