| 其他書名 | Identification and Evaluation of Alaskan Vegetation from Airphotos with Reference to Soil, Moisture and Permafrost Conditions : a Preliminary Paper |
| 出版 | Field Operations Branch, Permafrost Division, 1949 |
| URL | http://books.google.com.hk/books?id=pHixP7RKGREC&hl=&source=gbs_api |
| EBook | FULL_PUBLIC_DOMAIN |