Sources:
https://www.nature.com/articles/nature25447#MOESM4
https://www.wideopeneats.com/citrus-hybrids/
https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/citrus-medica
https://hort.purdue.edu/newcrop/morton/citron.html
https://www.edenproject.com/learn/for-everyone/plant-profiles/citron
https://books.openedition.org/pcjb/2184?lang=en#bibliography
https://www.myjewishlearning.com/article/history-of-sukkot/
https://reformjudaism.org/saga-citron
https://jewishreviewofbooks.com/articles/3467/the-peculiar-history-of-the-etrog/