| 其他書名 | R & D Centers, Policy Centers, Educational Laboratories, [and] Early Childhood Laboratory |
| 出版 | U.S. Department of Health, Education and Welfare, Office of Education, 1969 |
| URL | http://books.google.com.hk/books?id=ownVTG735D0C&hl=&source=gbs_api |
| EBook | FULL_PUBLIC_DOMAIN |