Cita APA (7a ed.)

EcoSummit Halifax, N.S., Costanza, R., & J�rgensen, S. E. (2002). Understanding and solving environmental problems in the 21st century: Toward a new, integrated hard problem science. Elsevier.

Cita Chicago Style (17a ed.)

EcoSummit Halifax, N.S., Robert Costanza, y Sven Erik J�rgensen. Understanding and Solving Environmental Problems in the 21st Century: Toward a New, Integrated Hard Problem Science. Amsterdam ; Boston: Elsevier, 2002.

Cita MLA (8a ed.)

EcoSummit Halifax, N.S., et al. Understanding and Solving Environmental Problems in the 21st Century: Toward a New, Integrated Hard Problem Science. Elsevier, 2002.