# Formula for finding integer points in fundamental parallelepipeds — reference for proof?

Does anyone know of a text where I can find a proof like the one found in Lemma 5.2 of here?

It's a formula for the integer points inside the fundamental parallelepiped of a simplicial integral cone. I'm writing a paper and I don't really want to reproduce the proof, but I'd also like to reference somewhere that sets it out a bit nicer.

Thanks a lot!

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