Não informado. (1961). Illinois agricultural economics. University of Illinois, Department of Agricultural Economics.
Citação do estilo Chicago (17ª ed.)Não informado. Illinois Agricultural Economics. Urbana, Ill: University of Illinois, Department of Agricultural Economics, 1961.
Citação MLA (8ª ed.)Não informado. Illinois Agricultural Economics. University of Illinois, Department of Agricultural Economics, 1961.
警告：这些引文格式不一定是100％准确.