@incollection{PurBot:88,
  publisher = {Babe\c s-Bolyai University},
  title = {Independence in power algebra of an universal algebra},
  olume = {Preprint no. 5},
  author = {Purdea, Ioan and Both, Nicolae},
  year = 1988,
  pages = {2--21},
  series = {Faculty of Mathematics Research Seminaries},
}