Fresh water the precious resource.
| Egile nagusia: | |
|---|---|
| Formatua: | Liburua | 
| Argitaratua: | 
        GArden City, N. Y.
          Natural Press for the American Museum of Natural History
    
        1967
     | 
| Gaiak: | 
| Egile nagusia: | |
|---|---|
| Formatua: | Liburua | 
| Argitaratua: | 
        GArden City, N. Y.
          Natural Press for the American Museum of Natural History
    
        1967
     | 
| Gaiak: |