@article{Rud:68,
  journal = {Proc. Edinburgh Math. Soc. (2)},
  volume = {16},
  title = {On functions and equations in distributive lattices},
  author = {Rudeanu, Sergiu},
  year = {1968},
  fjournal = {Proceedings of the Edinburgh Mathematical Society. Series II},
  pages = {49--54},
}