Combinatorial Optimization — Polyhedra and Efficiency

The standard reference for algorithms over polyhedra. I keep coming back to it whenever a problem reduces to LP, matching, flow, or matroids — particularly Chapters on submodularity (Vol B) for fairness work and on shortest paths / flows (Vol A) for the Min-Cost Flow project. Notation is dense; the payoff is that nearly every nontrivial fact has a verifiable proof.