Otto Warmbier, American Student Released From North Korea, Dies - The New York Times
https://www.nytimes.com/2017/06/19/us/otto-warmbier-north-korea-dies.htmlOtto Warmbier: what happened in the North Korean jail that led to American’s death? | South China Morning Post
https://www.scmp.com/magazines/post-magazine/long-reads/article/2169308/otto-warmbier-what-happened-north-korean-jail-ledThe Untold Story of Otto Warmbier, American Hostage | GQ
https://www.gq.com/story/otto-warmbier-north-korea-american-hostage-true-story