TWEETEN, Luther G. et al. Long-Term Viability of U.S. Agriculture. Council for Agricultural Science and Technology (CAST), Ames, U.S.A., 1988. DOI: 10.62300/mgaf4r09. Disponível em: https://publications.cast-science.org/CAST/article/view/242. Acesso em: 2 jul. 2026.