1. Precambrian micro-organisms from the central Eastern Desert of Egypt;Aboul Ela;Egyptian Journal Geology,1989
2. Micro-organisms three billion years old from the Precambrian of South Africa;Barghoorn;Science,1966
3. Micro-organisms from the Gunflint Chert;Barghoorn;Science,1965
4. The Krivoy Rog basin;Belevtsev,1983
5. Palaeoenvironmental setting of iron-formations in the depositional basin of the Transvaal Supergroup, South Africa;Beukes,1983