APA (7th ed.) Citation

Buchan, J. (1994). The thirty-nine steps. Oxford Bookworms.

Chicago Style (17th ed.) Citation

Buchan, John. The Thirty-nine Steps. Oxford: Oxford Bookworms, 1994.

MLA (9th ed.) Citation

Buchan, John. The Thirty-nine Steps. Oxford Bookworms, 1994.