Luciano JV, Barrada JR, Aguado J, Osma J, García-Campayo J. Bifactor analysis and construct validity of the HADS: a cross-sectional and longitudinal study in fibromyalgia patients. Psychological Assessment. 2014 Jun;26(2):395-406.
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.