Treasures of Taliesin: Seventy Six Unbuilt Designs - Butterfly Wing Bridge, project - FLLW Archive Drawing Number 4921.001: Perspective (fig. 45b)

Drawing Citation

Drawing 001 - Perspective, early sketch
Butterfly Wing Bridge, project (is cited in)
Treasures of Taliesin: Seventy Six Unbuilt Designs (published in)