1. American Gas Association, various issues, Gas facts: A statistical record of the gas utility industry (American Gas Association, Arlington, VA).
2. American Petroleum Institute, various issues, Basic petroleum data book (American Petroleum Institute, Washington, DC).
3. Error components and seemingly unrelated regressions;Avery;Econometrica,1977
4. Pooling cross section and time series data in the estimation of a dynamic model: The demand for natural gas;Balestra;Econometrica,1966
5. The short-run residential demand for electricity;Barnes;Review of Economics and Statistics,1981