Hasse's classification of Quaternion algebras (over number fields)

Question

I am looking for the reference to Hasse's original publication classifying the Quaternion algebras over a number field $K$. The statement in the paper or book should read something like:

``Two Quaternion algebras over a number field $K$ are isomorphic iff they are ramified at the same number of places"

Answer 1

As detailed here, Hasse introduced an invariant, now known as the Hasse invariant in two papers (here and here) to classify central simple algebras.