Hong J, Novick D, Montgomery W, Aguado J, Dueñas H, Peng X, Haro JM. Should unexplained painful physical symptoms be considered within the spectrum of depressive symptoms? Clin Pract Epidemiol Ment Health. 2015 Mar 31;11:130-9. doi: 10.2174/1745017901511010130
Dysktra LA, Granger AL. Interactions between the delta agonist SNC80, and the mu agonists, morphine, buprenorphine, and butorphanol in squirrel monkeys. Nida Res Monogr. 2000;180:65.
Gfroerer J, Lessler J, Parsley (Edwards) T. Studies of nonresponse and measurement error in the national household survey on drug abuse. Nida Res Monogr. 1997;167:273-95.