If there are three or more authors of a work use et al. after the first author's surname.
Example:
Ashley et al. (2014) state that...
OR
...(Ashley et al., 2014).
Example:
Burin et al. (2019) conclude that....
OR
...(Burin et al., 2019).
Last name, Initial(s)., Last name, Initial(s)., & Last name, Initial(s). (Year). Article title. Journal title in italics, Volume number in italics(issue or part number), page numbers. DOI (if available)
Ashley, C., Kibbe, S., & Thornton, S. (2014). Experiential learning in second life: A simulation in retail management. Atlantic Marketing Journal, 3(2), 94-113.
Burin, D., Kilteni, K., Rabuffetti, M., Slater, M., & Pia, L. (2019). Body ownership increases the interference between observed and executed movements. PLOS ONE, 14(1), Article e0209899. https://doi.org/10.1371/journal.pone.0209899
NB: In the reference list include all authors, however if a reference has 21 or more authors, the first 19 authors are listed followed by ... followed by the final author.
Example:
Kalnay, E., Kanamitsu, M., Kistler, R., Collins, W., Deaven, D., Gandin, L., Iredell, M., Saha, S., White, G., Woollen, J., Zhu, Y., Chelliah, M., Ebisuzaki, W., Higgins, W., Janowiak, J., Mo, K. C., Ropelewski, C., Wang, J., Leetmaa, A.,…Joseph, D. (1996). The NCEP/NCAR 40-year reanalysis project. Bulletin of the American Meteorological Society, 77(3), 437-471. https://doi.org/10.1175/1520-0477(1996)077<0437:TNYRP>2.0.CO;2