References

Reference 1. M.M. Kent and K.A. Crews, World Populations: Fundamentals of Growth, 1990, Population Reference Bureau, Washington, D.C.

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 Malcolm McPherson.


Copyright © 1998 Central Virginia Governor's School for Science and Technology Lynchburg, VA