@article{CTT100652778,
  author = {Gudlaugur Thorbergsson and Masaaki Umehara},
  title = {A refinement of Foreman's four vertex theorem and its dual version},
  journal = {Kyoto Journal of Mathematics},
  year = 2013,
}

@article{CTT100652772,
  author = {Syuntaro Oono and Tetsuya Ozawa and Masaaki Umehara},
  title = {Closed Planar curves without inflections},
  journal = {Proc. Amer. Math. Soc.},
  year = 2013,
}