@inproceedings{monotoneksubmodularfunctionmaximization,
  title = {Monotone k-Submodular Function Maximization with Size Constraints},
  author = {Naoto Ohsaka and Yuichi Yoshida},
  year = {2015},
  booktitle = {NeurIPS 2015 12},
  url = {http://papers.nips.cc/paper/5709-monotone-k-submodular-function-maximization-with-size-constraints},
}