Noah's options: Initial cost estimates of a national system of habitat conservation areas in the United States

Shaffer, M. L., Scott, J. M., & Casey, F. (2002). Noah’s options: Initial cost estimates of a national system of habitat conservation areas in the United States. BioScience, 52(5), 439–443. https://doi.org/10.1641/0006-3568(2002)052[0439:NSOICE]2.0.CO;2