@incollection{CorPur:88,
  publisher = {Babe\c s-Bolyai University},
  title = {Reduction of $m+1$-group and its extensions to the same group},
  olume = {Preprint no. 5},
  author = {Corovei, Ilie and Purdea, Ioan},
  year = 1988,
  pages = {63--68},
  series = {Faculty of Mathematics Research Seminaries},
}