1. Scanning the business environment;Aguilar,1967
2. Information utilization by policy-makers in Nigeria, part II: Characteristics of information sources used;Aiyepeku;Journal of Information Science,1982
3. The concept of corporate strategy;Andrews,1970
4. Corporate strategy: An analytic approach to business policy for growth and expansion;Ansoff,1965
5. International business;Asheghian,1990