5Diaz E, Fern6ndez J, Canto N, et al. Carbon and ecological footprints as tools for evaluating the environmental impact of coal mine ventiia- tion air [ J ]. Ecological h~dicators ,2012,18 : 126 - 130.
6Cagiao J, Gemez B, Dom6nech J L, et al. Calculation of the corpm'ate carbon footprint of the cement industry by the application of MC3 methodology [ J ]. Ecological Indicators,2011,11 ( 6 ) : 1526 - 1540.
7Gemechu E D, Butnar I, Lop M, et al. Environmental tax on productsand services based on their carbon footprint: A case study of the pulp and paper sector[ J]. Energy Policy,2012,50:336 - 344.
8Sgouridis S, Philippe A, Hansman R J. Air transportation in a carbon constrained world : Long-term dynamics of policies and strategies for mitigating the carbon footprint of commerciai aviation[J]. Transpor- tation Research Part A:Policy and Practice,2011,45 ( 10 ) :1077 - 1091.
9Yi L Q. The analysis on carbon footprint of catering products in high - start hotels during operation: Based on investigation conducted in parts of high - star hotels in Jinan [ J ]. Energy Procedia,2011 ( 5 ) : 890 - 894.