@article{PurBot:90,
  journal = {Studia Univ. Babe\c s-Bolyai, Ser. Mathematica},
  volume = {36},
  title = {Considerations concerning power algebra},
  author = {Purdea, Ioan and Both, Nicolae},
  year = 1990,
  pages = {3--8},
  number = {1},
}