Health (3) Programs (2) Surveys (2) Books (2) Salud (2) Estudio (2) Información (2) matériau (1) information (1) santé (1) évaluation (1) moyen de communication (1) liberté (1) index (1) Colombie (1) Selection (1) Area (1) Surveys (1) AIDS (Disease) in adolescence (1) Labor (1) Area (1) Teenagers (1) Youth (1) Transplantation of organs, tissues, etc (1) Students (1) Social classes (1) Sex (Biology) (1) Sex (1) Sampling (1) Respect (1)