Cita APA (7a ed.)

Hudelson, S., & Rigg, P. U. (1987). Hopscotch: Course book : level four.

Cita Chicago Style (17a ed.)

Hudelson, Sara, y Pat Urzúa Rigg. Hopscotch: Course Book : Level Four. New York, 1987.

Cita MLA (9a ed.)

Hudelson, Sara, y Pat Urzúa Rigg. Hopscotch: Course Book : Level Four. 1987.