1. [AOAC]. Association of Analytical Communities (1996) Official methods of analysis of AOAC International. 16th ed. AOAC International, Gaithersburg, MD, USA, 1995 p
2. [CIREN]. Centro de Información de Recursos Naturales (2003) Descripciones de Suelos, Materiales y Símbolos. Estudio Agrológico X Región, Publicación 123. CIREN, Santiago, Chile, 200 p
3. [INN]. Instituto Nacional de Normalización (2005) Agua Potable- Parte 1-Requisitos. Norma Chilena Oficial NCh409/1.Of2005. Santiago, Chile, 15 p
4. [ISO]. International Organization for Standardization (1998) 14911:1998 water quality — determination of dissolved Li+, Na+, NH4
+, K+, Mn2+, Ca2+, Mg2+, Sr2+ and Ba2+ using ion chromatography — method for water and waste water. International Organization for Standardization, Geneva, 18 p
5. [WRB]. World Reference Base for Soil Resources (2006) A framework for international classification, correlation and communication. 2nd ed. World Soil Resources Reports No. 103. FAO, Rome, 145 p