Cita APA (7th ed.)

Giggins, L. W., & Shoebridge, D. J. (1970). Tense drills. Longman.

Cita Chicago (17th ed.)

Giggins, L. W., i D. J. Shoebridge. Tense Drills. Londres: Longman, 1970.

Cita MLA (9th ed.)

Giggins, L. W., i D. J. Shoebridge. Tense Drills. Longman, 1970.