@article{18211,
  author = {Roberts C. and Henderson-Smart D. and Algert C. and Morris J.},
  title = {Trends in twin births in NSW, Australia, 1990-1999},
  year = {2002},
  journal = {International Journal of Gynecology & Obstetrics},
  volume = {78},
  pages = {213-9},
  language = {eng},
}