1. D.K.Harrison: Finite and infinite primes for rings and fields, Memoirs Amer. Math. Soc. 68 (1966).
2. T.Kanzaki and K.kitamura: Notes on infinite primes of a commutative ring, to appear in Mathematica Japonica Vol. 28, No.5.
3. T.Kanzaki: On signatures on rings, preprint.