Cita APA (7th ed.)

Hills, E. C. (1941). With topical charts, direct-method exercises and alternative English-Spanish exercises (New ed.). D.C. Heath & co.

Cita Chicago (17th ed.)

Hills, Elijah Clarence. With Topical Charts, Direct-method Exercises and Alternative English-Spanish Exercises. New ed. Boston: D.C. Heath & co, 1941.

Cita MLA (9th ed.)

Hills, Elijah Clarence. With Topical Charts, Direct-method Exercises and Alternative English-Spanish Exercises. New ed. D.C. Heath & co, 1941.