Bourne JE, Sauchelli S, Perry R, Page A, Leary S, England C, Cooper AR. Health benefits of electrically-assisted cycling: a systematic review. Int J Behav Nutr Phy. 2018 Nov 21;15(1):116. doi: 10.1186/s12966-018-0751-8
Watts (Wideman) K, McAvinchey G, Quiroz R. Language services in survey research. ATA Chronicle. 2002 Jul;31(7):36-7.
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.