1. Wada, K.Allophane and imogolite. InMinerals in Soil Environments. 2nd Ed.; Dixon, J.B.; Weed, S.B., Eds.; Soil Sci. Soc. Am. Book Series No. 1; SSSA: Madison, 1989; 1051–1087.
2. Schwertmann, U.; Taylor, R.M.Iron oxides. InMinerals in Soil Environments. 2nd Ed.; Dixon, J.B.; Weed, S.B., Eds.; Soil Sci. Soc. Am. Book Series No. 1; SSSA: Madison, 1989; 379–438.
3. Drees, L.R.; Wilding, L.P.; Smeck, N.E.; Senkayi, A.L.Silica in soils: Quartz and disordered silica polymorphs. InMinerals in Soil Environments. 2nd Ed.; Dixon, J.B.; Weed, S.B., Eds.; Soil Sci. Soc. Am. Book Series No. 1; SSSA: Madison, 1989; 913–974.
4. Properties and Quantitative Estimation of Poorly Crystalline Components in Sesquioxidic Soil Clays*
5. Amorphous Clay Constituents of Soils