APA (7e ed.) Bronvermelding

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

Chicago (17e ed.) Bronvermelding

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

MLA (9e ed.) Bronvermelding

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