- Author: University of Oxford., Cartwright Justin
- Language: English
- Year: 2008
- Author: University of Oxford, Carey John
- Language: English
- Year: 2014
- Author: Brian KwobaRose ChantilukeAthinangamso Nkopo
- Language: English
- Year: 2018
- Author: M. G. Brock M. C. Curthoys
- Language: English
- Year: 1984
- Author: Crawford Sally, Elsner Jaś, Ulmschneider Katharina
- Language: English
- Year: 2017