Hagan JF, Shaw JS, Duncan PM, eds. Bright Futures: Guidelines For Health Supervision of Infants, Children, and Adolescents [pocket guide]. 4th ed. Elk Grove Village, IL: American Academy of Pediatrics; 2017. Copyright by the AAP.

Pictorial stages of normal puberty as described by Marshall and Tanner.
Reproduced with permission from Muir A, Pediatr Rev. 2006;27:374. Copyright by the AAP.