Least squares completions for nonlinear differential algebraic equations. Stephen L. Campbell — 1993 Numerische Mathematik
Numerically generated path stabilizing controllers: Use of preliminary feedback Dirk von Wissel; Ramine Nikoukhah; François Delebecque; Stephen L. Campbell — 1995 Kybernetika
Nontrivial isometries on s p ( alpha). Campbell, Stephen L. — 1982 International Journal of Mathematics and Mathematical Sciences