Methods for assessment of fish production in fresh waters.
| Fformat: | Llyfr | 
|---|---|
| Cyhoeddwyd: | 
        London
          International Biological Programme, 1968
    
        1968
     | 
| Pynciau: | 
| Fformat: | Llyfr | 
|---|---|
| Cyhoeddwyd: | 
        London
          International Biological Programme, 1968
    
        1968
     | 
| Pynciau: |