Funkhouser, E., Fellows, J. L., Gordan, V. V., Rindal, D. B., Foy, P. J., & Gilbert, G. H. (2014). Supplementing online surveys with a mailed option to reduce bias and improve response rate: The National Dental PBRN. J Public Health Dent.

Funkhouser, Ellen, Jeffrey L. Fellows, Valeria V. Gordan, D. Brad Rindal, Patrick J. Foy, i Gregg H. Gilbert. "Supplementing Online Surveys With a Mailed Option to Reduce Bias and Improve Response Rate: The National Dental PBRN." J Public Health Dent 2014.

Funkhouser, Ellen, et al. "Supplementing Online Surveys With a Mailed Option to Reduce Bias and Improve Response Rate: The National Dental PBRN." J Public Health Dent 2014.