| value | technique | year | title_of_literature<MAX120col.> | journal<MAX120col.> | vol | page | name<MAX80col.> |
| 0.12 | ICPES |
1990.04 | Personal communication, Geological Survey of India | | | | B.G.Rao |
| 0.42 | ICPMS |
1993.04 | Simultaneous determination of thirty-seven trace elements in twenty-eight international rock standards by ICP-MS | Geost. Newsletter | 17 | 81-97 | CD.Garbe-Schonberg |
| 0.43 | ICPMS |
1994 | Personal Communication,WSU GeoAnalytical Laboratory, USA | | | | C. Knaack, S. Cornelius and P. Hooper |
| 0.43 | ICPMS |
2000 | Personarl Communication,Washington State University | | | | D. Johnson |