Sen Gupta, J. <br/><br/>
Determination Of Traces Of Rare-Earth Elements. Yttrium And Thorium In Several International Geological Reference Samples And Comparison Of Data With Other Published Values 

 -  SEGEMAR  1977 
<br/><br/> Geological Survey Of Canada, Geostandards Newsletter, Vol.1, N�2 (octubre) Pags.149-155