How to rephrase this statement in a paper? "Due to a limited number of pages, ..." How do you say in your paper that "due to a limited number of pages allowed, I'm not going to discuss the details how and from where this equation is derived..."

It is a conference paper, and they "might" ask us in future to publish our papers in more details in a dedicated special issue of journal X. I need to skip some calculations as I'm limited by pages, and no reference I have to refer, just some derivations.
Details are omitted to conserve space.


Terse. Because you don't want your explanation to cause you to go over the page limit.