Chartres made new use of Gothic flying butresses & vaulting.
The Spiritual Imagination: Why what we do with our buildings
Chartres
Explore Chartres Cathedral, a Gothic masterpiece - French Moments
What Is Gothic Architecture?
Chartres Cathedral, Paris – Architecture Revived
French Gothic architecture - Wikiwand
ArtOdysseys - the Emergence of Gothic Architecture
Gothic Cathedral Floor Plan
Chartres Cathedral: the south transept with rose window and triple
The spire of the Cathedral Notre-Dame de Paris. Not medieval, but
Gargoyle of the Day: Chartres Cathedral, France - A Scholarly Skater