- Author: Kornelia Freitag
- Language: English
- Year: 2015
- Author: Kyle Pivetti
- Language: English
- Year: 2015
- Author: Birgit Däwes
- Language: English
- Year: 2013
- Author: J. Brooks Bouson
- Language: English
- Year: 2005
- Author: Mark Cirino, Mark P. Ott
- Language: English
- Year: 2013
- Author: Julia Rawa
- Language: English
- Year: 2005
- Author: F. Ndi, Hart Fishkin, Festus Fru Ndeh
- Language: English
- Year: 2013
- Author: Savran David
- Language: English
- Year: 1999
- Author: Moraru Christian
- Language: English
- Year: 2005
- Author: Montefiore Jan
- Language: English
- Year: 2003