PaperOn greedy algorithms, partially ordered sets, and submodular functionsB.L. Dietrich, A.J. HoffmanIBM J. Res. Dev
PaperTwo remarks on compositive matricesEmilie Haynsworth, A.J. HoffmanLinear Algebra and Its Applications
PaperA note on almost regular matricesA.J. Hoffman, P. Wolfe, et al.Linear Algebra and Its Applications