Issue No.03 - May/June (1973 vol.6)
The PMS notation was developed to describe the physical structure of computer systems in terms of a small number of elementary components for textbook (Bell and Newell, 1971).
C.G. Bell, D. Siewiorek, "PMS: A Notaton to Describe Comuter Sructures", Computer, vol.6, no. 3, pp. 19-21, May/June 1973, doi:10.1109/C-M.1973.217034