-The type of the reference file (i.e. the reference source) is identified by a single letter after the file name and enclosed in square brackets. The specific types are as follows: m- monographs and ordinary books; C- prose collection; N- newspaper articles; Journal articles; D- thesis; R- report.

-References should be numbered in the order in which they appear in the text.

-The format of references shall conform to the national standard GB/T77 14-20 15 "Rules for the Description of References in Information and Literature".