R. Bruce Elder, Harmony and dissent: film and avant-garde art movements in the early twentieth century, ISBN978-1-55458-028-6, p. 32
Sokolina, Anna P. "Biology in Architecture: the Goetheanum Case Study. " The Routledge Companion to Biology in Art and Architecture, edited by Terranova, Charissa and Meredith Tromble, 52-70. New York and London: Routledge, 2016. 546p. https://books.google.com/books?id=klPUDAAAQBAJ&pg=PT144&dq=onepage.
The original essay was published in the journal Lucifer-Gnosis in 1907 and can be found in Steiner’s collected essays, Lucifer-Gnosis 1903–1908,
GA34. This essay was republished as an independent brochure in 1909; in a Prefatory note to this edition, Steiner refers to recent lectures on the subject. An English translation can be found in The Education of the Child: And Early Lectures on Education (first English edition 1927, Second English edition 1981, London and New York, 1996 edition ISBN978-0-88010-414-2)
The original essay was published in the journal Lucifer-Gnosis in 1907 and can be found in Steiner’s collected essays, Lucifer-Gnosis 1903–1908,
GA34. This essay was republished as an independent brochure in 1909; in a Prefatory note to this edition, Steiner refers to recent lectures on the subject. An English translation can be found in The Education of the Child: And Early Lectures on Education (first English edition 1927, Second English edition 1981, London and New York, 1996 edition ISBN978-0-88010-414-2)