Klossner, N. Jayne, Introductory Maternity Nursing (2005): "The fetal stage is from the beginning of the 9th week after fertilization and continues until birth"
Oxford University Press. (n.d.). Prenatal, adj., Etymology. In Oxford English dictionary. Retrieved June 27, 2025, from https://doi.org/10.1093/OED/1003485597
Anderson SE, Dallal GE, Must A (April 2003). "Relative weight and race influence average age at menarche: results from two nationally representative surveys of US girls studied 25 years apart". Pediatrics. 111 (4 Pt 1): 844–850. doi:10.1542/peds.111.4.844. PMID12671122.
Mouritsen A, Aksglaede L, Sørensen K, Mogensen SS, Leffers H, Main KM, Frederiksen H, Andersson AM, Skakkebaek NE, Juul A (April 2010). "Hypothesis: exposure to endocrine-disrupting chemicals may interfere with timing of puberty". Int. J. Androl. 33 (2): 346–59. doi:10.1111/j.1365-2605.2010.01051.x. PMID20487042.
Anderson SE, Dallal GE, Must A (April 2003). "Relative weight and race influence average age at menarche: results from two nationally representative surveys of US girls studied 25 years apart". Pediatrics. 111 (4 Pt 1): 844–850. doi:10.1542/peds.111.4.844. PMID12671122.
Mouritsen A, Aksglaede L, Sørensen K, Mogensen SS, Leffers H, Main KM, Frederiksen H, Andersson AM, Skakkebaek NE, Juul A (April 2010). "Hypothesis: exposure to endocrine-disrupting chemicals may interfere with timing of puberty". Int. J. Androl. 33 (2): 346–59. doi:10.1111/j.1365-2605.2010.01051.x. PMID20487042.
"For girls, puberty begins around 10 or 11 years of age and ends around age 16. Boys enter puberty later than girls-usually around 12 years of age-and it lasts until around age 16 or 17." "Teenage Growth & Development: 11 to 14 Years". Palo Alto Medical Foundation/pamf.org. Archived from the original on 2018-04-05. Retrieved 2013-11-09.
Hamilton-Fairley, Diana. Obstetrics and Gynaecology(PDF). Lecture Notes (Second ed.). Blackwell Publishing. Archived from the original(PDF) on 2018-10-09. Retrieved 2013-11-09.
"For girls, puberty begins around 10 or 11 years of age and ends around age 16. Boys enter puberty later than girls-usually around 12 years of age-and it lasts until around age 16 or 17." "Teenage Growth & Development: 11 to 14 Years". Palo Alto Medical Foundation/pamf.org. Archived from the original on 2018-04-05. Retrieved 2013-11-09.
Hamilton-Fairley, Diana. Obstetrics and Gynaecology(PDF). Lecture Notes (Second ed.). Blackwell Publishing. Archived from the original(PDF) on 2018-10-09. Retrieved 2013-11-09.