Cita APA

ebrary, Inc, Hill, J., & Gale, T. (2009). Ecotourism and environmental sustainability: Principles and practice. Ashgate.

Citación estilo Chicago

ebrary, Inc, Jennifer Hill, and Tim Gale. Ecotourism and Environmental Sustainability: Principles and Practice. Farnham, England ; Burlington, VT: Ashgate, 2009.

Cita MLA

ebrary, Inc, et al. Ecotourism and Environmental Sustainability: Principles and Practice. Ashgate, 2009.