APA

Helm J. H., Katz L., . (2001). Young investigators: the project approach in the early years. New York: Teachers College Press.

Chicago

Helm Judy Harris, Katz Lilian, . 2001. Young investigators: the project approach in the early years. New York: Teachers College Press.

Harvard

Helm J. H., Katz L., . (2001). Young investigators: the project approach in the early years. New York: Teachers College Press.

MLA

Helm Judy Harris, Katz Lilian, . Young investigators: the project approach in the early years. New York: Teachers College Press. 2001.