Kindergarten Guide. Kraus-Boelte. 113-145.
Koehler's Kindergarten Practice. Tr. by Mary Gurney. 31, 32.
The Kindergarten. H. Goldammer. 105-110.
Stones of Venice. John Ruskin.
Architecture, Mysticism, and Myth. W. K. Lethaby.
The Sources of Architectural Types. Spencer's Essays, vol. ii. page 375.
The Two Paths. John Ruskin. (Chapter on Influence of Imagination in Architecture.)
Discourses on Architecture. E. E. Viollet-le-Duc. Tr. by Henry Van Brunt. (First and Second Discourses.)