http://www.cyh.com/HealthTopics/HealthTopicDetailsKids.aspx?p=335&np=289&id=1774
http://www.webmd.com/sex-relationships/guide/your-guide-female-reproductive-system
http://www.webmd.com/sex-relationships/guide/male-reproductive-system
http://www.webmd.com/infertility-and-reproduction/guide/sperm-and-semen-faq
http://www.betterhealth.vic.gov.au/bhcv2/bhcarticles.nsf/pages/menstrual_cycle
http://www.womenshealth.gov/publications/our-publications/fact-sheet/menstruation.html
http://www.menstruation.com.au/fertility/howdoesconception.html
http://implantationspotting.net/signs-of-successful-implantation-why-it-is-important-to-stay-optimistic/
http://www.babymed.com/implantation/what-implantation
http://www.mydr.com.au/babies-pregnancy/baby-s-development-in-the-womb
http://www.webmd.com/sex-relationships/guide/your-guide-female-reproductive-system
http://www.webmd.com/sex-relationships/guide/male-reproductive-system
http://www.webmd.com/infertility-and-reproduction/guide/sperm-and-semen-faq
http://www.betterhealth.vic.gov.au/bhcv2/bhcarticles.nsf/pages/menstrual_cycle
http://www.womenshealth.gov/publications/our-publications/fact-sheet/menstruation.html
http://www.menstruation.com.au/fertility/howdoesconception.html
http://implantationspotting.net/signs-of-successful-implantation-why-it-is-important-to-stay-optimistic/
http://www.babymed.com/implantation/what-implantation
http://www.mydr.com.au/babies-pregnancy/baby-s-development-in-the-womb