@article{DimitrovaFernandesKoppitz2016,
  author    = {Ilinka Dimitrova and Vitor H. Fernandes and J{\"o}rg Koppitz},
  title     = {A note on generators of the endomorphism semigroup of an infinite countable chain},
  journal   = {Journal of Algebra and its Applications},
  volume    = {16},
  number    = {2},
  doi       = {10.1142/S0219498817500311},
  year      = {2016},
}