- Illinois State Water Survey.
- Illinois War Council. 1941-
- Illinois.
- Illinois. Aquatic Biology Section.
- Illinois. Board of live stock commissioners.
- Illinois. Bureau of Family Nutrition.
- Illinois. Center for Aquatic Ecology.
- Illinois. Department of Conservation.
- Illinois. Department of Forestry.
- Illinois. Department of Natural Resources.
- Illinois. Department of Public Works and Buildings.
- Illinois. Department of Registration and Education,
- Illinois. Department of Registration and Education.
- Illinois. Department of Transportation. Wetland Vegetative and Soils Survey Program.
- Illinois. Dept. of Agriculture.
- Illinois. Dept. of Conservation.
- Illinois. Dept. of Conservation. Bureau of Land and Historic Sites.
- Illinois. Dept. of Energy and Natural Resources.
- Illinois. Dept. of Energy and Natural Resources. Office of Research and Planning.
- Illinois. Dept. of Human Services. Bureau of Family Nutrition.
- Illinois. Dept. of Natural Resources.
- Illinois. Dept. of Natural Resources. Office of Scientific Research and Analysis.
- Illinois. Dept. of Public Health.
- Illinois. Dept. of Registration and Education.
- Illinois. Dept. of Transportation. Wetlands Unit.
- Illinois. Division of Animal Industry.
- Illinois. Division of Energy and Environmental Assessment.
- Illinois. Division of Environmental Health.
- Illinois. Division of Fisheries,
- Illinois. Division of Forest Resources.
- Illinois. Division of Forestry.
- Illinois. Division of Stallion Registration.
- Illinois. Division of State Parks.
- Illinois. Division of Water Pollution Control.
- Illinois. Energy and Environmental Assessment Division.
- Illinois. Environmental Protection Agency.
- Illinois. Environmental Protection Agency. Office of Community Relations.
- Illinois. Environmental Protection Agency. Office of Public Information.
- Illinois. Framework Advisory Committee.
- Illinois. Game and Fish Commission.
- Illinois. General Assembly 1859-
- Illinois. Horticultural Board of Control.
- Illinois. LTRMP Havana Field Station.
- Illinois. Natural History Survey Division
- Illinois. Natural History Survey Division. Aquatic Biology Section.
- Illinois. Natural History Survey Division. Center for Biodiversity.
- Illinois. Natural History Survey Division. Center for Wildlife Ecology.
- Illinois. Natural History Survey Division. LTRMP Havana Field Station.
- Illinois. Natural History Survey Division. River Research Laboratory.
- Illinois. Office of Community Services.
- Illinois. Office of Realty and Environmental Planning.
- Illinois. Office of Resource Conservation.
- Illinois. Rivers and lakes commission.
- Illinois. Secretary of state.
- Illinois. Section of Faunistic Surveys and Insect Identification.
- Illinois. Section of Wildlife Research.
- Illinois. Stallion Registration Board.
- Illinois. State Board of Fish Commissioners.
- Illinois. State Entomologist.
- Illinois. State Fish Commission.
- Illinois. State Geologist
- Illinois. Water Resources and Land Use Priorities Task Force.
- Illman, W I
- Illman, William I.
- Illmann, Gudrun
- Illmensee, Karl
- Illoldi-Rangel, Patricia
- Illustrated American Expedition to the San Juan Region (1892)
- Ilmonen, Jari
- Ilnomac Gardens.
- Ilot, Charles
- Ilse, Hugo, 1835-1900
- Iltchenco, Janaina
- Iltis, A
- Iltis, Hugh H.
- Iltis, Hugo, 1882-1952
- Ilunga Wa Ilunga, Edouard
- Ilyas, Orus
- Ilyas, S
- Ilyashenko, Vadim
- Ilyina, Elena Vjatcheslavovna
- Ilyina, Irina
- Ilyukh, Mikhail P.
- Ilyukhin, Evgeny
- Im Thurn, Everard Ferdinand, Sir, 1852-1932
- Im, Hyeong-Woo
- Imada, Masako
- Imada, Yume
- Imadate, Gentaro
- Imafuku, Michio
- Imahara, Yukimitsu
- Imahori, K
- Imai, Bruna Yuri Pinheiro
- Imai, Kiyohiro
- Imai, Soichi
- Imaizumi, Hiroki
- Imaizumi, Tomohito
- Imakawa, Angela Maria
- Imam, Ekwal
- Imamoglu, H Oguz
- Imamura, Hisashi
- Imani, Sohrab
- Imanpour Namin, Javid
- Imansyah, M Jeri
- Imao, Keinen.
- Imas, María
- Imaseki, T.
- Imatomi, Maristela
- Imba Lliquin, Segundo M
- Imba, Segundo M
- Imbamba, S. K.
- Imbassahy, Caio Amitrano de Alencar
- Imbeau, Louis
- Imbert Palafox, José Luis
- Imbert, François
- Imberti, Iseppo,
- Imberti, Santiago
- Imbimbo, Hélio Rubens Victorino
- Imbiriba, Emir Palmeira
- Imboma, Titus
- Imbres, Caroline
- Imbrie, John.
- Imbrogno, Sandra
- Imbrozio Barbosa, Reinaldo
- Imbun, Paul
- IMC Consulting Group.
- Imdorf, Anton
- Imdorf, Gregory J
- Imecs, István
- Imentai, Aiman
- Imes, Marion.
- Imešek, Mirna
- Imfeld, S
- Imhof, Othmar Emil, 1855-1936
- Imhof, Thomas A
- Imhoff, Johannes F, 1951-
- Imhoff, Ludwig, 1801-1868
- Imin, Kamin
- Imison, John, 1788
- Imlay Company.
- Imlay, John D.
- Imlay, Tara Leah
- Imler, Ralph H.
- Immel, Harald
- Immelman, K
- Immelman, K L
- Immelmann, Gertrud.
- Immelmann, Klaus.
- Immerman, Ferdinand
- Immers, Janis
- Immerz, Peter
- Immler, Eva
- Immler, Rolf M, 1944-
- Imms, A. D. (Augustus Daniel), 1880-1949
- Imms, Alison
- Imori, Tatsuo
- Imoulan, Abdessamad
- Imp. Tourfaut,
- Impecuniosus.
- Impekoven, Monica, 1936-
- Imper, David
- Imper. Monast. s. Ambrosii majoris.
- Imperato, Ferrante, 1550-1625
- Imperato, Filippo
- Imperato, Francesco.
- Imperatorskai︠a︡ akademīi︠a︡ nauk (Russia)
- Imperatorskai︠a︡ akademīi︠a︡ nauk (Russia). Fiziko-matematicheskoe otdielenīe.
- Imperatorskai͡a akademīi͡a nauk (Russia). Istoriko-filologicheskoe otdi͡elenīe.
- Imperatorskai︠a︡ akademīi︠a︡ nauk (Russia). Zoologicheskiĭ muzeĭ.
- Imperatorskai︠a︡ akademīi︠a︡ nauk (Russia). Zoologicheskīĭ muzeĭ.
- Imperatorskai︠a︡ akademīi︠a︡ nauk i khudozhestv (Russia)
- Imperatorskīǐ botanicheskīǐ sad Petra Velikago
- Imperatorskii institut eksperimentalnoi meditsiny (Russia).
- Imperatorskīĭ kharʹkovskīĭ universitet.
- Imperatorskii Sankt-Peterburgskii botanicheskii sad.
- Imperatorskoe obshchestvo liubitelei estestvoznaniia, antropologii i etnografii (Russia)
- Imperatorskoe obshchestvo liubitelei estestvoznaniia, antropologii i etnografii (Russia). Kommissiia dlia issledovaniia fauny Moskovskoi gubernii.
- Imperatorskoe obshchestvo selskago khoziaistva iuzhnoi Rossii.
- Imperatorskoe russkoe geograficheskoe obshchestvo
- Imperatorskoe russkoe geograficheskoe obshchestvo. Fizicheskii otdiel.
- Imperatorskoe russkoe geograficheskoe obshchestvo. Sibirskaia ekspeditsiia (1859-)
- Imperatorskoe Sankt-Peterburgskoe Obshchestvo Estestvoispytateleĭ.
- Imperatriz-Fonseca, Vera Lúcia
- Imperial Agricultural Research Institute (India)
- Imperial Bureau of Entomology.
- Imperial Flower Garden.
- Imperial Forest College (Dehradun, India)
- Imperial Institute (Great Britain)
- Imperial Institute of Agricultural Research (India)
- Imperial Institute of Entomology.
- Imperial Iris Gardens,
- Imperial Nurseries.
- Imperial royal agricultural association of Carniola.
- Imperial Seed and Plant Co.
- Imperial Walnut Nursery.
- Imperiali Typographeo.
- Implement Company.
- Imprimerie A. Carro,
- Imprimerie Becquet.
- Imprimerie Crété,
- Imprimerie d'A. René et Cie.,
- Imprimerie D'A. Sirou Et Desquers,
- Imprimerie D'A. Sirou,
- Imprimerie d'Amédée Gratiot,
- Imprimerie de Bacquenois,
- Imprimerie de Casimir,
- Imprimerie de Cosson,
- Imprimerie de Crapelet (Paris, France)
- Imprimerie de Crapelet (Paris, France),
- Imprimerie de De Breuk & Smits,
- Imprimerie de Decourchant,
- Imprimerie de Didot, jeune, Pierre, 1761-1853
- Imprimerie de É. Martinet,
- Imprimerie de F.G. Levrault,
- Imprimerie De Fain Et Thunot (Paris, France),
- Imprimerie de Fain et Thunot,
- Imprimerie de Fain,
- Imprimerie de J.G. Neubert,
- Imprimerie de Langlois.
- Imprimerie de Le Normant,
- Imprimerie de Louis Guérin,
- Imprimerie de Malassis le Jeune,
- Imprimerie de Millevoy,
- Imprimerie de Mme. Ve. Bouchard-Huzard,
- Imprimerie de P. Trenel,
- Imprimerie de P.A. Élies,
- Imprimerie de Plassan,
- Imprimerie de Raymond Noubel,
- Imprimerie de Terzuolo,
- Imprimerie de Weissenbruch père,
- Imprimerie Dondey-Dupré,
- Imprimerie du Dépôt des lois,
- Imprimerie E. Thunot Et Cie (Paris, France),
- Imprimerie Et Fonderie De Fain
- Imprimerie Lemercier et cie,
- Imprimerie Lemercier et cie.
- Imprimerie Lemercier,
- Imprimerie nationale (France)
- Imprimerie royale (France)
- Imprimerie Vve P. LaRousse et cie.,
- Imran, Amna
- Imre, Haydar Birol
- Imre, István
- Imshaug, Henry A.
- Imués-Figueroa, Marco Antonio
- Imura, Satoshi
- Inaba, Akihiko
- Inaba, Nobuharu
- Inaba, Tadaaki
- Inäbnit, Thomas