Snodgrass, M. M., & Wallace, L. T. (1980). Agriculture, economics, and resource management (2d ed.). Prentice-Hall.
Lua i Stíl Chicago (17ú heag.)Snodgrass, Milton Moore, agus Luther T. Wallace. Agriculture, Economics, and Resource Management. 2d ed. Englewood Cliffs, N.J.: Prentice-Hall, 1980.
Lua MLA (9ú heag.)Snodgrass, Milton Moore, agus Luther T. Wallace. Agriculture, Economics, and Resource Management. 2d ed. Prentice-Hall, 1980.