@article{ng05a,
  title =	 {Yard crane scheduling in port container terminals},
  volume =	 29,
  issn =	 {{0307904X}},
  url =
                  {http://linkinghub.elsevier.com/retrieve/pii/S0307904X04001167},
  doi =		 {10.1016/j.apm.2004.09.009},
  number =	 3,
  journal =	 {Applied Mathematical Modelling},
  author =	 {W Ng and K Mak},
  year =	 2005,
  pages =	 {263--276}
}