Issue No. 07 - July (1970 vol. 19)
The Gray code counter is stated to be an accidental result of the logical design of a binary counter which has two memory elements per stage.
Binary counter, Gray code, pulse counter, relay counter.
"Comment on "Gray Code Counter"", IEEE Transactions on Computers, vol. 19, no. , pp. 653-654, July 1970, doi:10.1109/T-C.1970.223000