1. Department of Environmental Management, Kotebe University of Education, Addis Ababa, Ethiopia
2. Department of Management, Kotebe University Education, Addis Ababa, Ethiopia
3. Department of Business Management, University of Johannesburg, South Africa
4. Department of Rural Development and Agricultural Extension, Wollega University, Ethiopia
5. Department of Biology, Kotebe University of Education, Addis Ababa, Ethiopia
6. Department of Epidemiology and Biostatistics, University of California, San Francisco, CA, USA