Reference 1. M.M. Kent and K.A. Crews, World
Populations: Fundamentals of Growth, 1990, Population Reference Bureau, Washington,
Reference 2, Fig. 2.
"Coalbed Methane", Malcolm McPherson, Energy Outlook Virginia Center for
Coal and Energy, Virginia Poly Tech and State University, Spring 1996. Courtesy of
Copyright © 1998 Central Virginia Governor's School for Science and Technology Lynchburg, VA