| value | technique | year | title_of_literature<MAX120col.> | journal<MAX120col.> | vol | page | name<MAX80col.> |
| 1.9 | FAA |
1987.07 | Personal communication, UNDP Philippines | | | | I.Rubeska |
| 1.9 | AA |
1987.07 | Personal communication, BMG, Philippines | | | | E.M.Macalalad |
| 1.8 | FLUOR |
1988.02 | Personal communication, Tsukuba University, Japan | | | | H.Onishi and H.Koshima |
| 1.8 | OES |
1988.02 | Personal communication, USSR Academy of Sciences Siberian Branch | | | | V.P.Afonin |
| 1.8 | OES |
1989.1 | Determination of trace abundances of Ag, B, Ge, Mo, Sn, Tl and W in geochemical reference samples by atomic emission spectrography | Geost. Newsletter | 13 | 269-272 | A.I.Kuznetsova and N.L.Chumakova |
| 1.960 | AA |
1989.1 | Determination of thallium in eighty-seven geochemical reference samples by atomic absorption spectrometry | Geost. Newsletter | 13 | 277-281 | S.Terashima |
| 1.77 | 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 |