Hatch, M. C., Figa-Talamanca, I., & Salerno, S. (1999). Work stress and menstrual patterns among American and Italian nurses. Scandinavian Journal of Work, Environment & Health, 144–150; Fenster, L., Waller, K., Chen, J., Hubbard, A. E., Windham, G. C., Elkin, E., & Swan, S. (1999). Psychological stress in the workplace and menstrual function. American Journal of Epidemiology, 149(2), 127–134.