United States. Bureau of Entomology. (1903). Fruit-tree bark-beetle (Scolytus rugulosus Ratz.). [publisher not identified].
Chicago Style (17th ed.) CitationUnited States. Bureau of Entomology. Fruit-tree Bark-beetle (Scolytus Rugulosus Ratz.). [Washington]: [publisher not identified], 1903.
MLA (9th ed.) CitationUnited States. Bureau of Entomology. Fruit-tree Bark-beetle (Scolytus Rugulosus Ratz.). [publisher not identified], 1903.
Warning: These citations may not always be 100% accurate.