Frank Neumann Dirk Sudholt Carsten Witt Rigorous Analyses for the Combination of Ant Colony Optimization and Local Search. 132-143 2008 ANTS Conference http://dx.doi.org/10.1007/978-3-540-87527-7_12 conf/antsw/2008 db/conf/antsw/ants2008.html#NeumannSW08