How do I cite multiple sources by the same author published in the same year?

In Harvard style referencing, to distinguish between two sources by the same author that were published in the same year, you add a different letter after the year for each source:

  • (Smith, 2019a)
  • (Smith, 2019b)

Add ‘a’ to the first one you cite, ‘b’ to the second, and so on. Do the same in your bibliography or reference list.