https://www.ncbi.nlm.nih.gov/books/NBK470302/
http://repository.ub.ac.id/id/eprint/2662/3/BAB%202%20tesis%20Ambar-156070400111018.pdf
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7738700/
http://eprints.undip.ac.id/12378/1/2004PPDS3624.pdf
https://emedicine.medscape.com/article/2188931-overview
