(en) Grant Hayter-Menzies, Imperial Masquerade : The Legend of Princess Der Ling, Hong Kong University Press, , 444 p. (ISBN978-962-209-881-7, lire en ligne).
(en) Larry Clinton Thompson, William Scott Ament and the Boxer Rebellion, Jefferson, NC: McFarland, (lire en ligne), p. 84-85
(en) Col Michael Lee Lanning, Mercenaries : Soldiers of Fortune, from Ancient Greece to Today#s Private Military Companies, Random House Publishing Group, , 288 p. (ISBN978-0-307-41604-9, lire en ligne)