Não informado. Virginia agricultural economics. Virginia Polytechnic Institute, Department of Agricultural Economics and Rural Sociology.
Citação do estilo Chicago (17ª ed.)Não informado. Virginia Agricultural Economics. Blacksburg, Va: Virginia Polytechnic Institute, Department of Agricultural Economics and Rural Sociology.
Citação MLA (8ª ed.)Não informado. Virginia Agricultural Economics. Virginia Polytechnic Institute, Department of Agricultural Economics and Rural Sociology.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.