Gaya APA
GESELL, A., Ilg, F, L. (1949).
Child development : an introduction to the study of human growt .
New York:
Harper and Row.
Gaya MLA
GESELL, Arnold., Ilg, Frances, L.
"Child development : an introduction to the study of human growt".
New York:
Harper and Row,
1949.
Buku.