Sleep disturbances among teen workers from a public school of São Paulo, Brazil - Steluti, Josiane; Fischer, Frida Marina; Nagai, Roberta; Teixeira, L. R.; Zinn, Lílian Cardoso de Souza; Repullo Júnior, Rodolpho; Soares, N. S. (International Congress on Occupational Health. Renewing a century of commitment to a healthy, safe and productive working life, 2006)