Não informado. Plant Immigrants. U.S. Department of Agriculture, Bureau of Plant Industry.
Citação do estilo Chicago (17ª ed.)Não informado. Plant Immigrants. Washington: U.S. Department of Agriculture, Bureau of Plant Industry.
Citação MLA (8ª ed.)Não informado. Plant Immigrants. U.S. Department of Agriculture, Bureau of Plant Industry.
Atenció: Aquestes cites poden no estar 100% correctes.