1. Inorganic index to the powder diffraction file;A.S.T.M.;Am. Soc. Testing Mater. Publ.,1967
2. Imogolite in volcanic ash soils of Chile;Besoain;Geoderma,1968
3. Some properties of volcanic ash soils;Birrell;World Soil Res. Rept.,1964
4. The x-Ray Identification and Crystal Structures of Clay Minerals;Brown,1961
5. Climosequence of ash-derived soils in the Central Cordillera of Colombia;Cortes,1972