Computation Theory of Cellular Automata (1984) (PDF)
Cryptography with Cellular Automata (1985) (PDF)
Random Sequence Generation by Cellular Automata (1986) (PDF)
Approaches to Complexity Engineering (1986) (PDF)
Note: Since 1987 Stephen Wolfram's intellectual
have primarily been described in his books on Mathematica
and A New Kind of Science rather than academic articles.