Proposition 6
Tag 04SV, permanent. Cite it as [Bourbaki, Tag 04SV].
Commutative Algebra, chapter VI, § 2. Places
Let be a field and a subring of For an element to be integral over it is necessary and sufficient that every place of which is finite on be finite at
This is also a consequence of Theorem 3 of § 1, no. 3.
Bourbaki puts the proof directly after the statement, so what is above is the statement and its proof together.