| 其他書名 | An Interpretative Study of the Data Collected in the National Survey of Visual Instruction in Elementary and Secondary Schools |
| 出版 | U.S. Government Printing Office, 1938 |
| URL | http://books.google.com.hk/books?id=P7i36KlI3OUC&hl=&source=gbs_api |
| EBook | FULL_PUBLIC_DOMAIN |