ebrary, Inc, Dowling, R. K., & Fennell, D. A. (2003). Ecotourism policy and planning. CABI Pub..
芝加哥风格引文ebrary, Inc, Ross Kingston Dowling, 与 David A. Fennell. Ecotourism Policy and Planning. Wallingford, Oxon, UK ; Cambridge, MA, USA: CABI Pub., 2003.
MLA引文ebrary, Inc, et al. Ecotourism Policy and Planning. CABI Pub., 2003.
警告：这些引文格式不一定是100％准确.