Thanks for answering so quickly and for clarifying this!

Hello Chelsea, I have a question regarding in-text citations of two references with the same first author and year, but different second and third authors. I know that I cannot shorten the subsequent references to Smith et al. (2015), but have to use as many author names to distinguish the two references, e.g. Smith, Brady, et al. (2015) and Smith, Connor, et al. (2015). My question now is: When do I start this distinguishing, if one of the references is cited much later in the text than the other, i.e. Smith, Brady et al. (2015) is cited in the introduction, and Smith, Connor, et al. (2015) appears for the first time in the discussion. Do I have still to cite the Smith, Brady reference as Smith, Brady, et al. (2015) even before the second reference appears? Or can I cite it as Smith et al. (2015) in the introduction and only start citing it as Smith, Brady, et al. (2015) after the second reference is cited as well? Your help would be very much appreciated! Many thanks in advance, Lena