APA   Click to copy
Giulietti, M., & Montanucci, E. (2009). Abstract ovals of order 9. Ars Combinatoria, 91, 297–301.

Chicago/Turabian   Click to copy
Giulietti, M., and E. Montanucci. “Abstract Ovals of Order 9.” Ars Combinatoria 91 (2009): 297–301.

MLA   Click to copy
Giulietti, M., and E. Montanucci. “Abstract Ovals of Order 9.” Ars Combinatoria, vol. 91, 2009, pp. 297–301.

@article{giulietti2009a,
  title = {Abstract ovals of order 9},
  year = {2009},
  journal = {Ars Combinatoria},
  pages = {297-301},
  volume = {91},
  author = {Giulietti, M. and Montanucci, E.}
}