I'm looking for a reference for the existence of a finitelyadditive product probability measure for an arbitrary family of finitelyadditive probability measures. It's easy to prove, but I'd like to have a citation rather than to include a notationally messy proof. If I was looking for the harder countablyadditive version, I guess I'd cite Kakutani (the result is credited in that case to LomnickiUlam, but I've heard that they have a mistake in the proof).
