https://www.chicagotribune.com/news/ct-xpm-1985-06-28-8502110841-story.html
https://historycollection.com/10-crazy-things-never-knew-tunnel-rat-soldiers-vietnam-war/
https://en.wikipedia.org/wiki/Tunnel_rat
https://www.nytimes.com/2018/02/09/opinion/vietnam-war-tunnel-rat.html
https://e.vnexpress.net/news/travel/places/the-most-dangerous-creatures-in-vietnam-3526414.html