More information...
- http://www.britannica.com/EBchecked/topic/420752/Notre-Dame-de-Paris
- http://go.grolier.com/print?id=0290170-00&&product_id=ea&authcode=eafull
- http://go.grolier.com/print?id=0254620-0&&product_id=gme&authcode=gme
- http://www.britannica.com/EBchecked/topic/518043/Saint-Peters-Basilica
- http://www.britannica.com/EBchecked/topic/497731/Renaissance
- http://academic.brooklyn.cuny.edu/english/melani/cs6/ren.html