Gaya APA

Piggott, R., Barraclough, G. (1998). Crucible of the Middle Ages, The: The Ninth and Tenth Centuries in European History . London, United Kingdom: The Folio Society.

Gaya MLA

Piggott, Reginald., Barraclough, Geoffrey. "Crucible of the Middle Ages, The: The Ninth and Tenth Centuries in European History". London, United Kingdom: The Folio Society, 1998. Academic.