| Publication Type: | Journal Article |
| Year of Publication: | 1940 |
| Authors: | H. H. Plough, Jones N. |
| Journal: | Carnegie Institute of Washington Publication, No 517 |
| Pagination: | 47-60 |
| Publication Type: | Journal Article |
| Year of Publication: | 1940 |
| Authors: | H. H. Plough, Jones N. |
| Journal: | Carnegie Institute of Washington Publication, No 517 |
| Pagination: | 47-60 |