Intente links en:Similares en:
Merlo, Juan, Basile Chaix, Min Yang, John Lynch y Lennart Rastam. 2005. A Brief Conceptual Tutorial of Multilevel Analysis in Social Epidemiology: Linking the Statistical Concept of Clustering to the Idea of Contextual Phenomenon. Journal of Epidemiology Community Health 59 (6): 443–449.