1. “Ethiopian-Statistical Abstracts 1984”, Central Statistical Office, Addis Ababa, December 1986.
2. “Proceeding of an International Sympsium of Fibre Reinforced Concrete”, Publication Sp − 44, American Concrete Institute, Detroit, Michigan 1974.
3. “Proceedings of RILEM Symposium on Fibre Reinforced Cement and Concrete”, 1975, Construction Press Ltc. Lancaster, England.
4. “Proceedings of RILEM Symposium on Testing and Test Methods of Fibre Cement Composite”, 1978.
5. “Proceeding of the Symposium on Fibrous Concrete”, 1980, Construction Press Ltc. Lanacaster, England.