L. H. Wilder. . “Male and female hookworms, Anchylostoma duodenale (European hookworm), figures for "Report upon the prevalence and geographic distribution of hookworm diseaseÃ¢â‚¬Â¦" by C. W. Stiles (1903), Public Health and Marine-Hospital Service of the United States, Hygienic Laboratory Bulletin No. 10. .” Special Collections, USDA National Agricultural Library. Accessed December 6, 2022, https://www.nal.usda.gov/exhibits/speccoll/items/show/8105.