@article{MauPur:64b,
  journal = {Studia Univ. Babe\c s-Bolyai, Ser. Math.-Phys.},
  title = {Inele pentru care subgrupurile aditive sunt subinele},
  author = {Maurer, I. and Purdea, Ioan},
  year = 1964,
  pages = {13--15},
  number = {2},
}