Groenwold RH, Klungel OH, Altman DJ, van der Graaf Y, Hoes AW, Moons KG, Rivero E, Fortuny J, PROTECT WP2. Adjustment for continuous confounders: an example of how to prevent residual confounding. Can Med Assoc J. 2013 Mar 19;185(5):401-6. doi: 10.1503/cmaj.120592
Gascon M, Verner MA, Guxens M, Grimalt JO, Forns J, Ibarluzea J, Lertxundi N, Ballester F, Llop S, Haddad S, Sunyer J, Vrijheid M. Evaluating the neurotoxic effects of lactational exposure to persistent organic pollutants (POPs) in Spanish children. Neurotoxicology. 2013 Jan;34:9-15. doi: 10.1016/j.neuro.2012.10.006