APA   Click to copy
Edwards, K. A., Vowles, K. E., & Witkiewitz, K. (2020). Opioids. Encyclopedia of Personality and Individual Differences, 3342–3347.

Chicago/Turabian   Click to copy
Edwards, Karlyn A, Kevin E Vowles, and Katie Witkiewitz. “Opioids.” Encyclopedia of Personality and Individual Differences (2020): 3342–3347.

MLA   Click to copy
Edwards, Karlyn A., et al. “Opioids.” Encyclopedia of Personality and Individual Differences, Springer International Publishing, 2020, pp. 3342–47.

@article{edwards2020a,
  title = {Opioids},
  year = {2020},
  journal = {Encyclopedia of Personality and Individual Differences},
  pages = {3342--3347},
  publisher = {Springer International Publishing},
  author = {Edwards, Karlyn A and Vowles, Kevin E and Witkiewitz, Katie}
}