Pseudo-total analysis for metallic elements in siliceous soil by acid digestion and flame atomic absorption spectrometryHödrejärv, Helvi; Vaarmann, AiniAnalytica chimica acta1999 / p. 293-301: ill https://www.sciencedirect.com/science/article/abs/pii/S0003267099004808#:~:text=Pseudo%2Dtotal%20analysis%20(PTA),found%20with%20Cu%20and%20Pb.