First, write the first reference and put the cursor in front of it.

Click the number library at the location shown in the figure and select "Define New Number Format" from the drop-down menu.

Modify the number format in the pop-up window. It is modified here according to the general reference number format and changed to "[1]". Select the alignment according to your preference, and then click OK.

You can then edit the second reference. After editing, add a reference to the corresponding text. First place the cursor where you want to Insert-& gt；, and then select Insert->; Cross reference. Select the citation to be inserted in the pop-up dialog box.

Select it, click Insert, finally select "[1]", and then select Start-> Superscript, get the superscript form label. Then follow this step.