https://stemcells.nih.gov/info/basics/1.htm
https://www.medicalnewstoday.com/info/stem_cell
How it works and how it is related to stem cells:
http://www.explorestemcells.co.uk/therapeuticcloning.html
https://science.howstuffworks.com/life/genetic/cloned-organ-transplant.htm
Successful organ cloning and transplantation:
http://www.cnn.com/2011/HEALTH/07/07/trachea.transplant/index.html
https://www.popsci.com/scientists-grow-transplantable-hearts-with-stem-cells
http://www.cnn.com/2006/HEALTH/conditions/04/03/engineered.organs/index.html
General
https://www.sciencedaily.com/releases/2016/04/160404152906.htm
In Planarian Worms
https://www.exploratorium.edu/imaging-station/research/planaria/story_planaria.pdf
In Salamanders
https://www.nature.com/news/2009/090701/full/news.2009.614.html