strange random number generator

I just tried to find out what the default random number generator of the Go programming language is. The source code for this RNG can be found in the file rng.go; the only reference in the source code is the cryptic comment algorithm by DP Mitchell and JA Reeds. Does anybody have a reference for this, or can at least identify DP Mitchell or JA Reeds? Some things I tried:

• I found one reference which claims that the Go random number generator is the same as used in Plan 9. The participants of this discussion seem to not know the origin of the method used.
• While searching for Mitchell in the context of random number generation, I found references to the following article: D. Mitchell, Nonlinear Key Generators, Cryptologia, vol. 14, pp. 350-354, 1990. I hoped that this article may allow me to find an affiliation for D. Mitchell, but unfortunately it seems to have been removed(!) from the journal. The table of contents shows a gap between pages 349 and 355.
• A Google search for mitchell reeds random number generator shows no obvious good candidates.

Any hints about where the algorithm comes from would be most welcome.