APA

Callo Concha D., Vlek L. P., Denich M., Martius C. & Manschadi A. (2009). An approach to environmental services assessment. [Alemania]: University of Bonn, Center for Development Research.

Chicago

Callo Concha Daniel, Vlek L.G Paul, Denich Manfred, Martius Christopher and Manschadi Ahmad. 2009. An approach to environmental services assessment. [Alemania]: University of Bonn, Center for Development Research.

Harvard

Callo Concha D., Vlek L. P., Denich M., Martius C. and Manschadi A. (2009). An approach to environmental services assessment. [Alemania]: University of Bonn, Center for Development Research.

MLA

Callo Concha Daniel, Vlek L.G Paul, Denich Manfred, Martius Christopher and Manschadi Ahmad. An approach to environmental services assessment. [Alemania]: University of Bonn, Center for Development Research. 2009.