A Process Specification Formalism Based on Static COLD. - Jos C. M. Baeten; Jan A. Bergstra; Sjouke Mauw; Gert J. Veltink (Algebraic Methods, 1989)

An Introduction to PSFd. - Sjouke Mauw; Gert J. Veltink (TAPSOFT, Vol.2, 1989)

A Proof Assistant for PSF. - Sjouke Mauw; Gert J. Veltink (CAV, 1991)

XP, an Experiment in Modular Specification. - Gert J. Veltink (FORTE, 1991)

The PSF Toolkit. - Gert J. Veltink (Comput. Networks ISDN Syst., 1993)