| value | technique | year | title_of_literature<MAX120col.> | journal<MAX120col.> | vol | page | name<MAX80col.> |
| <0.03 | AA |
1985 | Personal communication, Hiroshima Pref. Research Center Env., Japan | | | | T.Yamashige |
| <0.40 | INAA |
1989.03 | Personal communication, Musashi Institute of Technology, Japan | | | | S.Hirai and S.Suzuki |
| 0.011 | AA |
1991.01 | Personal communication, Geological Survey of Japan | | | | S.Terashima |
| 1 | XRF |
1996 | Personal communication,Bremen Univ., Germany | | | | M.Zuther |
| <2 | EXRF |
2002 | Personal Communication, Southern Connecticut State Univ., USA | | | | T. Fleming |