The first layer of the serial number of the paper is the chinese numerals Garton number, such as one, two and three;

The second layer contains Chinese characters and numbers in brackets, such as (1), (2) and (3);

The third layer is Arabic numerals with footnotes, such as 1.2.3.

The fourth level is that there are Arabic numerals in brackets, such as (1) (2) (3);

The fifth layer is circled Arabic numerals, such as ① ② ③;

The sixth floor is capitalized English letters, such as a.b.c;

The seventh layer is lowercase English letters, such as a.b.c

Nowadays, papers are often used to refer to articles that conduct research in various academic fields and describe academic research results, which are referred to as papers for short. It is not only a means to discuss problems in academic research, but also a tool to describe academic research results in academic exchanges. Including academic papers, graduation papers, dissertations, scientific papers, achievement papers and so on.