Objects
Rosen, Deborah Z, Lewis, Colin A, Illgner, Peter M. Palaeoclimatic and archaeological implications of organic-rich sediments at Tiffindell Ski Resort, near Rhodes, Eastern Cape Province, South Africa. 1999.
Lewis, Colin A, Illgner, Peter M. Fluvial conditions during the Holocene as evidenced by alluvial sediments from above Howison's Poort, near Grahamstown, South Africa. 1998.
Lewis, Colin A, Illgner, Peter M. Evidence of Quaternary glaciation in Southern Africa : moraines on the Bastervoetpad of the eastern Cape Drakensberg, South Africa. 2000.