Issue No.04 - April (1971 vol.20)
J.G. Bredeson , Dept. Elec. Eng. Pennsylvania State Univ.
This correspondence shows that the Necula  and Slagle, Chang. and Lee  methods for determining prime implicants are a mechanization of a method first given by Nelson , i. e., generating of all prime implicants by direct expansion of a conjunctive form to a disjunctive form.
Logical multiplication, prime-implicant generation.
J.G. Bredeson, P.T. Hultina, "Generation of Prime Implicants by Direct Multiplication", IEEE Transactions on Computers, vol.20, no. 4, pp. 475-476, April 1971, doi:10.1109/T-C.1971.223274