an Entity references as follows:
Prince Yongsan (Hangul: 용산원자, Hanja: 龍山元子, lit. 'Primary Son Yongsan'; 1325–1341) was a Goryeo Royal Prince and the heir successor to the throne as the only son of King Chungsuk of Goryeo and Princess Joguk. However, his mother died at 17 years old not long after he was born.