How to insert "double reference"

[Fernito]

Hi, this is my first post here. First of all, sorry if my english isn't very good, I'm a native spanish speaker.



Basically, what I want to do is the following:



As you can see, I want to put two references in the same line. You could think "hey, this guy is asking for something that he already did", but to take that screenshot I had to wrote the references "manually" What I want is that if I put a reference before that "double reference", the "double reference" updates automatically (in the example, it would become "4, 5").

I don't know if I explained myself well, I hope I did. If you've got any questions, please tell me. And thanks in advance for your help