Ralfs, E. M. (1921). An abstract of the legislation in force in the British Empire dealing with plant pests & diseases up to the year 1920. The Imperial bureau of entomology.
Chicago Style (17th ed.) CitationRalfs, E. Marguerite. An Abstract of the Legislation in Force in the British Empire Dealing with Plant Pests & Diseases Up to the Year 1920. London: The Imperial bureau of entomology, 1921.
MLA (9th ed.) CitationRalfs, E. Marguerite. An Abstract of the Legislation in Force in the British Empire Dealing with Plant Pests & Diseases Up to the Year 1920. The Imperial bureau of entomology, 1921.
Warning: These citations may not always be 100% accurate.