What does [4-6] in the upper right corner of the paper mean? Isn't there only one number if there is a reference? For example: management system and long-term mechanism. [ 1] 1 1
If that passage only quotes an article, that's what you said [4]; But a paragraph can quote several articles at the same time, so all these articles are listed. If the serial numbers of these files are consecutive, you can use the way you posted them [4-6].