United States. Department of Agriculture & United States. Division of Botany. (1901). Canada thistle. (Carduus arvenis (L.) Robs). [publisher not identified].
Chicago Style (17th ed.) CitationUnited States. Department of Agriculture and United States. Division of Botany. Canada Thistle. (Carduus Arvenis (L.) Robs). [Place of publication not identified]: [publisher not identified], 1901.
MLA (9th ed.) CitationUnited States. Department of Agriculture and United States. Division of Botany. Canada Thistle. (Carduus Arvenis (L.) Robs). [publisher not identified], 1901.
Warning: These citations may not always be 100% accurate.