An illustrated description of Romanesque architecture with its sources and identifying features - showing groundplans and cross-sections.
(Errata at bottom of the description)

With illustrations of some of the best known churches, cathedrals and abbeys-
Speyer Cathedral, Saint Maria, Lach, Pisa Cathedral, San Miniato al Monte, the Abbey of Cluny, Abbeye les Hommes Caen, Durham Cathedral, Peterborough Cathedral, St Michael's Hildesheim, the Collegiate Church Thum, Lisbon Cathedral.

ERRATA: The church shown at 40:35 is the church of St Gertrude, at Nivelles, Belgium, not the Cathedral at Tournus.

Images from Wiki Commons.