28 - Diccionario de la lengua española. Author, Madrid, Spain, 2001. [PUMA: apa apa-examples book doesn't_pass imported test]
16b - The relationship of school‐wide positive behavior support to academic achievement in an urban middle school. Psychology in the Schools, (43):701-712, July 2006. [PUMA: apa apa-examples doesn't_pass edited imported periodical test]
26 - Extracts from Piaget's theory (G. Gellerier & J. Langer, Trans.). In K. Richardson, and S. Sheldon (Eds.), Cognitive development to adolescence: A reader, 3-18, Erlbaum, Hilsdale, NJ, 1988. [PUMA: apa apa-examples book doesn't_pass imported test]