One of my earliest works was deriving equations which themselves were forms of Einstein’s field equations that described the state of the early universe, which may have had dominant viscous effects. I was delighted to learn that these equations were published in Springer’s Handbook of Spacetime Cosmology textbook.
Here is a snapshot of the textbook page citing these equations:
Relativity Digest 
One reply on “Equations Published in a Cosmology Textbook”
Congrats man!!