1. Connecting to Compete 2012 – Trade Logistics in the Global Economy - The Logistics Performance Index and its Indicators;Arvis,2012
2. (ATRI) American Transportation Research Institute. An Analysis of the Operational Costs of Trucking: 2011 Update. (accessed 28.12.12).
3. Avetisyan, M., Hertel, T., 2015. Impacts of Logistics Improvement on International Trade and Modal Choice. Working Paper, Texas Tech University.
4. Bank of Canada, 2013. Exchange Rates. .
5. (BLS) U.S. Bureau of Labor Statistics, 2012. May 2011 National Occupational Employment and Wage Estimates. .