Kindergarten Guide. J. and B. Ronge. 5-13.
Kindergarten Guide. Kraus-Boelte. 27-47.
Koehler's Kindergarten Practice. Tr. by Mary Gurney. 20-23.
Froebel and Education by Self-Activity. H. Courthope Bowen. 140-42.
Kindergarten Toys. Heinrich Hoffmann. 17-26.
Conscious Motherhood. E. Marwedel. 165, 166.
The Kindergarten. H. Goldammer. 49-70.