APA (7th ed.) Citation

Hubert, J., Porcher, J., & Volbach, W. F. (1969). Europe in the Dark Ages. Thames & Hudson.

Chicago Style (17th ed.) Citation

Hubert, Jean, Jean Porcher, and Wolfgang Fritz Volbach. Europe in the Dark Ages. London: Thames & Hudson, 1969.

MLA (8th ed.) Citation

Hubert, Jean, et al. Europe in the Dark Ages. Thames & Hudson, 1969.