https://www.nydailynews.com/news/national/oldest-janus-cat-world-frank-louie-dies-15-article-1.2033685

http://karlshuker.blogspot.com/2011/01/sonic-hedgehog-and-janus-cats.html

https://petknowledge.net/frank-and-louie-janus-cat-with-two-faces/

http://www.guinnessworldrecords.com/news/2014/12/worlds-longest-surviving-janus-cat-passes-away-62152/