1. Livelihood and Drought Coping Strategies of Farm Households in the Central Rift Valley, Ethiopia: Challenges for Agricultural Research;ICRA,1999
2. Development and improvement of highland maize in Ethiopia;Twumasi-Afriyie,2002
3. Regression Models for Categorical Dependent Variables Using Stata;Freese,2001
4. Microeconometrics: Methods and Applications;Cameron,2005
5. Introductory Economics: A Modern Approach;Wooldridge,2009