^Bergeron R, Debonnel G (February 1997). "Effects of low and high doses of selective sigma ligands: further evidence suggesting the existence of different subtypes of sigma receptors". Psychopharmacology. 129 (3): 215–24. doi:10.1007/s002130050183. PMID9084059. S2CID24537111.
^McLarnon J, Sawyer D, Church J (June 1994). "The actions of L-687,384, a sigma receptor ligand, on NMDA-induced currents in cultured rat hippocampal pyramidal neurons". Neuroscience Letters. 174 (2): 181–4. doi:10.1016/0304-3940(94)90016-7. PMID7526288. S2CID10876486.