% Not in the source data: doi, abstract
@article{mula-2006-flexible-constraints-fuzzy,
  author = {{J. Mula} and {R. Poler} and {J.P. Garcia}},
  title = {{MRP with flexible constraints: a fuzzy mathematical programming approach}},
  journal = {Fuzzy Sets and Systems},
  year = {2006},
  volume = {157},
  number = {1},
  pages = {74--97}
}