Friedrich Froebel's pedagogics of the Kindergarten or, his ideas concerning the play and playthings of the child / translated by Josephine Jarvis. - Fröbel, Friedrich Wilhelm, 1782-1852. (OLS)http://pul/name/44050; Jarvis, Josephine. (OLS)http://pul/name/96741 (D. Appleton and Company, 1907)
Bibliografia in nota.