https://en.wikipedia.org/wiki/Veryovkina_Cave

https://youtu.be/kNvfJYPYO60?si=Rs2UMnbZCl7Bo3_G

https://www.grunge.com/1116865/the-lethal-history-of-the-worlds-deepest-cave-veryovkina-cave/

https://www.atlasobscura.com/places/veryovkina-cave-deepest 

https://www.dailymail.co.uk/news/article-9884411/Body-climber-fell-death-worlds-deepest-cave-reclaimed-team-100.html 

https://www.base-mag.com/last-exit-from-the-secret-sea-exploration-veryovnika-cave/

https://www.nationalgeographic.com/adventure/article/flood-escape-deepest-cave-veryovkina-abkhazia

https://en.wikipedia.org/wiki/Pavel_Yevgenyevich_Demidov 

http://www.shonephotography.com/gallery/veryovkina-the-deepest-cave-in-the-world/?image=10749