$a Kp. Early years at school : a textbook for students of early childhood education / by Ilse Forest. - 1st ed., 3rd impr. - New York [etc.], 1949. $b Przedm.
670
$a LCA online
670
$a An experiment with a project curriculum / by Ellsworth Collings. - New York, 1927. $b Aut. wstępu (with an introduction by William H. Kilpatrick, prof. of Education, Teachers College, Columbia University)