Cita APA (7a ed.)

Tunstall, D. B., & Wansem, M. v. d. (1992). 1993 directory of country environmental studies: An annotated bibliography environmental and natural resource profiles and assesments. World Resources Institute.

Cita Chicago Style (17a ed.)

Tunstall, Daniel B., y Mieke van der Wansem. 1993 Directory of Country Environmental Studies: An Annotated Bibliography Environmental and Natural Resource Profiles and Assesments. Nueva York: World Resources Institute, 1992.

Cita MLA (9a ed.)

Tunstall, Daniel B., y Mieke van der Wansem. 1993 Directory of Country Environmental Studies: An Annotated Bibliography Environmental and Natural Resource Profiles and Assesments. World Resources Institute, 1992.