Sanderman, R.; Coyne, J. C.; Ranchor, A. V. (2006). "Age: Nuisance variable to be eliminated with statistical control or important concern?". Patient Education and Counseling. 61 (3): 315–316. doi:10.1016/j.pec.2006.04.002. PMID16731313.
Sanderman, R.; Coyne, J. C.; Ranchor, A. V. (2006). "Age: Nuisance variable to be eliminated with statistical control or important concern?". Patient Education and Counseling. 61 (3): 315–316. doi:10.1016/j.pec.2006.04.002. PMID16731313.