APA (7th ed.) Citation

Blyton, E., & Soper, E. (1970). Five on a secret trail. Knight books.

Chicago Style (17th ed.) Citation

Blyton, Enid, and Eilleen Soper. Five on a Secret Trail. Leicester: Knight books, 1970.

MLA (9th ed.) Citation

Blyton, Enid, and Eilleen Soper. Five on a Secret Trail. Knight books, 1970.

Warning: These citations may not always be 100% accurate.