Lower bound for the norm of a vertex-transitive graph. William L. Paschke — 1993 Mathematische Zeitschrift
Relative Commutant of a von Neumann Algebra in Its Crossed Product by a Group Action. William L. Paschke — 1978 Mathematische Zeitschrift
A numerical invariant for finitely generated groups via actions on graphs. William L. Paschke — 1993 Mathematica Scandinavica