Lauwerys, R., Roels, H., Genet, P., Toussaint, G., Bouckaert, A., & de Cooman, S. (1985). Fertility of Male Workers Exposed To Mercury-vapor Or To Manganese Dust - a Questionnaire Study. American Journal of Industrial Medicine, 7(2), 171-176. https://doi.org/10.1002/ajim.4700070208 (Original work published 1985)