APA   Click to copy
Rolla, G. (2014). A puzzle about normativity. Principia, 18(3), 323–336.

Chicago/Turabian   Click to copy
Rolla, Giovanni. “A Puzzle about Normativity.” Principia 18, no. 3 (2014): 323–336.

MLA   Click to copy
Rolla, Giovanni. “A Puzzle about Normativity.” Principia, vol. 18, no. 3, 2014, pp. 323–36.

@article{rolla2014a,
  title = {A puzzle about normativity},
  year = {2014},
  issue = {3},
  journal = {Principia},
  pages = {323-336},
  volume = {18},
  author = {Rolla, Giovanni}
}