Hannah Dahlen. (2017, 26 October). I’ve always wondered: what’s behind the belly button? Retrieved December 25, 2017, from https://theconversation.com/ive-always-wondered-whats-behind-the-belly-button-84598
Hannah Dahlen. (2015, 15 June). Delay clamping babies’ umbilical cords for better health and development. Retrieved December 25, 2017, from https://theconversation.com/delay-clamping-babies-umbilical-cords-for-better-health-and-development-42406
Umbilical cord. Retrieved December 25, 2017, from https://en.wikipedia.org/wiki/Umbilical_cord
The Institute for the Promotion of Teaching Science and Technology (IPST), Ministry of Education, a non-profit organization under the Thai government, developed SciMath as a website that provides educational resources in Science, Mathematics and Technology. IPST invites visitors to use its online resources for personal, educational and other non-commercial purpose. If there are any problems, please contact us immediately.