Mayo Foundation for Medical Education and Research. (n.d.). Mayo Clinic. Retrieved November 8, 2021, from https://www.mayoclinic.org/.
NHS. (n.d.). NHS choices. Retrieved November 8, 2021, from https://www.nhs.uk/.
Parenthood, P. (n.d.). Official site. Planned Parenthood. Retrieved November 8, 2021, from https://www.plannedparenthood.org/.