Hudelson, S. (1985). Hopscotch: Course book. Level two. Regents Publishing Company.
Citazione stile Chigago Style (17a edizione)Hudelson, Sarah. Hopscotch: Course Book. Level Two. Nueva York: Regents Publishing Company, 1985.
Citatione MLA (9a ed.)Hudelson, Sarah. Hopscotch: Course Book. Level Two. Regents Publishing Company, 1985.
Attenzione: Queste citazioni potrebbero non essere precise al 100%.