@misc{W2033909248,
  author = {Charles H. Bennett and H. J. Bernstein and Sandu Popescu and Benjamin Schumacher},
  title = {Concentrating partial entanglement by local operations},
  year = {1996},
  howpublished = {Physical Review A},
  doi = {https://doi.org/10.1103/physreva.53.2046}
}