John Rhodes A Homomorphism Theorem for Finite Semigroups. [Citation Graph (0, 0)][DBLP] Mathematical Systems Theory, 1967, v:1, n:4, pp:289-304 [Journal]
L. A. M. Verbeek Congruence Separation of Subsets of a Monoid with Applications to Automata. [Citation Graph (0, 0)][DBLP] Mathematical Systems Theory, 1967, v:1, n:4, pp:315-324 [Journal]
James A. Yorke Invariance for Ordinary Differential Equations. [Citation Graph (0, 0)][DBLP] Mathematical Systems Theory, 1967, v:1, n:4, pp:353-372 [Journal]