APA (7th ed.) Citation

Roesdahl, E. (1987). The Vikings. Penguin Books.

Chicago Style (17th ed.) Citation

Roesdahl, Else. The Vikings. Penguin Books, 1987.

MLA (9th ed.) Citation

Roesdahl, Else. The Vikings. Penguin Books, 1987.

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