«North Korea Says It's Holding U.S. Student for 'Hostile Act'». The New York Times(en inglés). 23 de enero de 2016. Consultado el 23 de enero de 2016. «Young Pioneer Tours, a China-based company that operates tours to North Korea, said in a statement that one of its clients, identified as "Otto," was being detained in the North Korean capital, Pyongyang».