Perceptions of immunization information systems for collecting pandemic H1N1 immunization data within Canada's public health community: a qualitative study. - Heidebrecht CL; Foisy J; Pereira JA; Quan SD; Willison DJ; Deeks SL; Finkelstein M; Crowcroft NS; Buckeridge DL; Guay M; Sikora CA; Kwong JC; et al. (BMC Public Health, 2010)