Resources and man a study and recommendations
| Awduron Corfforaethol: | , | 
|---|---|
| Awduron Eraill: | |
| Fformat: | Llyfr | 
| Iaith: | English | 
| Cyhoeddwyd: | San Francisco
          [published by] W. H. Freeman [for the National Academy of Sciences
    
        1969] | 
| Pynciau: | 


