A Simple Secure Pseudo-Random Number Generator (M82/65)
L. Blum, M. Blum and M. Shub

How to Exchange (Secret) Keys (M81/90)
Manuel Blum

On the Power of the Compass (or why Mazes are Easier to Search than Graphs) (M78/64)
M. Blum and W. Kozen

On the Capability of Finite Automata in 2 and 3 Dimensional Space (M78/35)
Manuel Blum and William J. Sakoda

Inductive Inference: A Recursion Theoretic Approach (M386)
L. Blum and M. Blum