见鬼的编辑需要我做这个事——
[20] See Supplemental Material [url], which includes Refs. [21-24].
[21] [first reference in Supplemental Material not already in Letter]
...
[24] [last reference in Supplemental Material not already in Letter]
也就是说,21-24在MAIN TEXT里面没有引用,但是需要生成并在引用20内被引……