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Ref. ID |   |   |   | 
Reference |   |  
  |  
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  |  |   |  
| CR58    | M. A. Catalán and F. R. Rico, An. R. Soc. Esp. Fis. Quim. 54, 301 (1958).    |  
|   |   |  
| E72     | K. B. S. Eriksson, Phys. Lett. A 41, 97 (1972).    |  
|   |   |  
| G62     | S. George, Ph. D. Thesis, Univ. British Columbia (1962).    |  
|   |   |  
| LP77    | B. Lindgren and H. P. Palenius, Sol. Phys. 53, 347 (1977).    |  
|   |   |  
| M00     | D. C. Morton, Astrophys. J. Suppl. Ser. 130, 403 (2000).    |  
|   |   |  
| M35     | D. C. Martin, Phys. Rev. 48, 938 (1935).    |  
|   |   |  
| MV74    | C. Morillon and J. Vergés, Phys. Scr. 10, 227 (1974). All 4p3nl levels from this reference have been increased by 0.23 cm-1, in accordance with [LP77]. |  
|   |   |  
| RG34    | J. E. Ruedy and R. C. Gibbs, Phys. Rev. 46, 880 (1934).    |  
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