An Optimization Algorithm for the Vehicle Routing Problem with Time Windows Based on Lagrangian Relaxation. - Niklas Kohl; Oli B. G. Madsen (Oper. Res., 1997)

A Framework for Constraint Programming Based Column Generation. - Ulrich Junker; Stefan E. Karisch; Niklas Kohl; Bo Vaaben; Torsten Fahle; Meinolf Sellmann (CP, 1999)

2-Path Cuts for the Vehicle Routing Problem with Time Windows. - Niklas Kohl; Jacques Desrosiers; Oli B. G. Madsen; Marius M. Solomon; François Soumis (Transp. Sci., 1999)

Constraint Programming Based Column Generation for Crew Assignment. - Torsten Fahle; Ulrich Junker; Stefan E. Karisch; Niklas Kohl; Meinolf Sellmann; Bo Vaaben (J. Heuristics, 2002)

Railway Crew Pairing Optimization. - Lennart Bengtsson; Rastislav Galia; Tomas Gustafsson; Curt Hjorring; Niklas Kohl (ATMOS, 2004)

Airline Crew Rostering: Problem Types, Modeling, and Optimization. - Niklas Kohl; Stefan E. Karisch (Ann. Oper. Res., 2004)