Borsodi, Anna, Michael Bruchas, Girolamo Caló, Charles Chavkin, MacDonald J. Christie, Olivier Civelli, Mark Connor, Brian M. Cox, Lakshmi A. Devi, Christopher Evans, Volker Höllt, Graeme Henderson, Stephen Husbands, Eamonn Kelly, Brigitte Kieffer, Ian Kitchen, Mary-Jeanne Kreek, Lee-Yuan Liu-Chen, Dominique Massot, Jean-Claude Meunier, Philip S. Portoghese, Stefan Schulz, Toni S. Shippenberg, Eric J. Simon, Lawrence Toll, John R. Traynor, Hiroshi Ueda, Yung H. Wong, Nurulain Zaveri, and Andreas Zimmer. “Opioid Receptors (version 2019.4) in the IUPHAR/BPS Guide to Pharmacology Database”. IUPHAR/BPS Guide to Pharmacology CITE 2019, no. 4 (September 16, 2019). Accessed August 12, 2020. http://journals.ed.ac.uk/gtopdb-cite/article/view/3202.