The numbers in superscript or brackets quoted in this paper represent the corresponding documents in the literature list. For example, "Laparoscopy can shorten the recovery time after abdominal surgery 1." Some magazines will say, "Laparoscopy can shorten the recovery time after abdominal surgery 1." There is no essential difference between superscript and bracket, but different magazines have different format requirements. In this way, readers can find the corresponding papers from the literature list according to the numbers marked in the papers, and can further find the source of opinions or conclusions. References are lists, 1, 2, 3. . . Most magazines are the same. But some of them are arranged according to the strokes of surnames. -For example, refer to 1. Zhang San and Li Si. 20 10. Application of laparoscopy in abdominal surgery. China medical journal XXX: XXX-XXX.