Zajonz, R., A. B. Müller, and N. C. Valentini. “The Influence of Environmental Factors in Motor and Social Performance of Children from the Suburb of Porto Alegre”. Journal of Physical Education (Maringá), Vol. 19, no. 2, Oct. 2008, pp. 159-71, https://periodicos.uem.br/ojs/index.php/RevEducFis/article/view/3220.