- Author: Elaine Housby
- Language: English
- Year: 2011
- Author: Kirwan Samuel
- Language: English
- Year: 2021
- Author: Carlos Sánchez González
- Language: English
- Year: 2018
- Author: World Bank
- Language: English
- Year: 2008
- Author: Asian Development Bank
- Language: English
- Year: 2016
- Author: Donald Vanthournout, Kurt Olson, John Ceisel
- Language: English
- Year: 2006