Pengfei He and Jin-Kao Hao. Iterated two-phase local search for the colored traveling salesmen problem. Engineering Applications of Artificial Intelligence Volume 97, 104018, January 2021, https://doi.org/10.1016/j.engappai.2020.104018

The benchmark instances, the certificates of our best solutions and the sources of our algorithm (as well as our implementation of the ABC algorithm compared in the paper) are available here.