1. The impact of gasoline prices on urban bus ridership;Agthe;Annals of Regional Science,1978
2. American Public Transportation Association, 2009. Downturn in Public Transit Ridership Reflects Economic Times. .
3. Combining forecasts;Armstrong,2001
4. Time Series Analysis: Forecasting and Control;Box,2008
5. Cartwright, William, 2010. Personal Communication. Mr. Cartwright is General Manager of the Metropolitan Tulsa Transit Authority.