Williamson, R. (1993). To meet early adolescent needs. National Association of Secondary School Principals.
Citazione stile Chigago Style (17a edizione)Williamson, Ronald. To Meet Early Adolescent Needs. Reston: National Association of Secondary School Principals, 1993.
Citatione MLA (9a ed.)Williamson, Ronald. To Meet Early Adolescent Needs. National Association of Secondary School Principals, 1993.
Attenzione: Queste citazioni potrebbero non essere precise al 100%.