Science (2) Research (2) Education (2) Educación (2) Investigación (2) éducation (2) Chili (1) Development (1) Childhood and youth (1) Specimens (1) Labor (1) Weights and measures (1) Walking (1) Vision (1) Trees (1) Students (1) Statistics (1) School children (1) Samples (Commerce) (1) Reformation (1) Quality of products (1) Population (1) Personality (1) Occupations (1) Object-teaching (1) Light (1) Id (Psychology) (1) Graphic methods (1) Goal (Psychology) (1) Gait in humans (1)