E. C. . de Freitas Gonçalves, A. E. . de Oliveira dos Santos, and J. A. . Martins Júnior, “Teaching practice: difficulties found by Physical Education teachers in the first five years of professional work: DOI: 10.15343/0104-7809.200731.4.6”, Mundo Saude, vol. 31, no. 4, pp. 494–499, Oct. 2007.