where to find ZCPR2, ZCPR3, ZCPR33, ZCPR34?

[Eric Smith]

I've become interested in ZCPR2, 3, 33, and 34, and am surprised at how
difficult it is to locate them online. Or maybe I'm just an idiot. Are they
out there somewhere?

It looks like ZCPR3 was on SIG/M volumes 184 to 192, but those specific
volumes seem to be missing from the SIG/M archives I can find.

I'm specifically NOT looking for NZ-COM or Z3PLUS.

Thanks!
Eric