龚勋. (2012). 最不可思议的地球未解之谜: Incredible unsolved mysteries of the earth. 汕头大学出版社.
Chicago (17e ed.) Bronvermelding龚勋. 最不可思议的地球未解之谜: Incredible Unsolved Mysteries of the Earth. 汕头大学出版社, 2012.
MLA (8e ed.) Bronvermelding龚勋. 最不可思议的地球未解之谜: Incredible Unsolved Mysteries of the Earth. 汕头大学出版社, 2012.
Let op: Deze citaties zijn niet altijd 100% accuraat.