1. Schellmann W (1981) Lateritisation Processes. Oxford and IBH, New Delhi, India, pp 1?10
2. Gardner LP (1970) Am Mineral 55:1380?1389
3. Gardner LP (1972) Am Mineral 57:292?300
4. Schorin H, LaBrecque JJ (1983) Geostandards Newslett 7:233?242
5. Schorin H, LaBrecque JJ (1986) Geol Surv India, 120:89?101