Schmitt CL, Allen JA, Kosa KM, Curry LE. Support for a ban on tobacco powerwalls and other point-of-sale displays: findings from focus groups. Health Educ Res. 2015 Feb;30(1):98-106. doi: 10.1093/her/cyu046.
Beach RH, Poulos C, Pattanayak SK. Farm economics of bird flu. Revue Canadienne D'agroeconomie. 2007 Dec 1;55(4):471-83.