Groenwold, R. H., Klungel, O. H., Altman, D. G., van der Graaf, Y., Hoes, A. W., & Moons, K. G. (2013). Adjustment for continuous confounders: An example of how to prevent residual confounding. Canadian Medical Association.

Groenwold, Rolf H.H., Olaf H. Klungel, Douglas G. Altman, Yolanda van der Graaf, Arno W. Hoes, and Karel G.M Moons. Adjustment for Continuous Confounders: An Example of How to Prevent Residual Confounding. Canadian Medical Association, 2013.

Groenwold, Rolf H.H., et al. Adjustment for Continuous Confounders: An Example of How to Prevent Residual Confounding. Canadian Medical Association, 2013.