Radochońska, Anna, Sylwia Dudzik, and Lidia Perenc. 2006. “Secular Changes in Age of Menarche in Girls from Boguchwała and Krasne Examined in 1976/77, 1988/89 and 2003/04 Years As Compared to Population of the Rzeszow Girls”. European Journal of Clinical and Experimental Medicine 4 (1):64–69. https://journals.ur.edu.pl/ejcem/article/view/13431.