# References for Gauss Composition using Galois Cohomology

Note: I have already posted this on stackexchange, but have not yet gotten a response.

What are some good references for the Gauss composition law on binary quadratic forms in terms of Galois Cohomology?

I guess to be more general, I should ask for an exposition in terms of etale cohomology, but the etale cohomology is exactly the Galois cohomology in the number field case anyhow.

Thanks.

• Stackexchange question: math.stackexchange.com/questions/671942/… – Noah Schweber Feb 12 '14 at 6:01
• right, that's the one that I asked mentioned in the above post (thank you for linking it; I suppose I should have done that). – Johannas Feb 12 '14 at 6:06