Where to find the Dirac equation for a physics paper

[raracon]

TL;DR

I am basically searching for a good source where Diracs Equasions resulting in negative energy are listed.

I am working on my physics paper and just realized that after explaining everything I did not add the equation. Now I am wondering where I can find a good source on them, so that I can add them.

 

[vanhees71]

It's in any textbook on QFT, e.g.,

M. D. Schwartz, Quantum field theory and the Standard
Model, Cambridge University Press, Cambridge, New York
(2014).