APA   Click to copy
Turing, A. M. On computable numbers, with an application to the Entscheidungsproblem. Journal of Mathematics, 345–363.

Chicago/Turabian   Click to copy
Turing, Alan Mathison. “On Computable Numbers, with an Application to the Entscheidungsproblem.” Journal of Mathematics (n.d.): 345–363.

MLA   Click to copy
Turing, Alan Mathison. “On Computable Numbers, with an Application to the Entscheidungsproblem.” Journal of Mathematics, pp. 345–63.

@article{alan-a,
  title = {On computable numbers, with an application to the Entscheidungsproblem},
  journal = {Journal of Mathematics},
  pages = {345-363},
  author = {Turing, Alan Mathison}
}