The materials contained in the paper, such as those published or written by others, or used to obtain degree certificates from other educational institutions, or any contribution made by tutors and colleagues working with the author to this research, should be clearly indexed and explained in the paper. The following is a list of letters, which are marked with different letters according to the types of references you use. But you have specific methods under Baidu.

M- (Monographs) Monographs (including works on history and chronology in ancient books), and books are also listed here.

C- (corpus) papers,

Newspaper articles,

Journal articles,

Doctoral dissertation,

R- (research) research report,

S- (standard) standard,

P- (patent) patent,

Monograph (article)