Beach RH, Poulos C, Pattanayak SK. Farm economics of bird flu. Revue Canadienne D'agroeconomie. 2007 Dec 1;55(4):471-83.
Kjeldsen BJ, Thorsen H, Whalley D, Kronborg O. Influence of follow-up on health-related quality of life after radical surgery for colorectal cancer. Scand J Gastroenterol. 1999 May;34(5):509-15.