Pimentel, D., Herdendorf, M., Eisenfeld, S., Olander, L., Carroquino, M., Corson, C., McDade, J., Chung, Y., Cannon, W., Roberts, J., Bluman, L., and Gregg, J., 1994, Achieving a secure energy future: Environmental and economic issues: Ecological Economics, v. 9, 19 p.