@article{cattaruzza2016multi,
  title={The multi-trip vehicle routing problem with time windows and release dates},
  author={Cattaruzza, Diego and Absi, Nabil and Feillet, Dominique},
  journal={Transportation Science},
  volume={50},
  number={2},
  pages={676--693},
  year={2016},
  publisher={INFORMS},
  doi = {http://dx.doi.org/10.1287/trsc.2015.0608} 
}