Circular / State of Illinois, Dept. of Registration and Education, Division of the State Geological Survey.

no.33-40; no.33-34 1938; no.34; no.39-47 1938-1939; no.23-24,27-28,32-34,39-45,47-49,52 inc. (1938-40); no.41-59; no.41; no.48-62 1939-1940; no.64-70 1940-1941; no.65-70; no.73-87 1941-1942; no.87-97; no.89-95; no.97-104 1943-1944; no.106-108 1944; no.59-72,74,77-79,81,83,93,97,99-100inc. (1940-45); no.110-119 1944-1945; no.121-141 (1945-48); no.142-159 (1948-50); no.156; no.174-185 (1951-53); no.166-200 1950-1955; no.186-192; no.186-205 (1954-55); 206-219 (1955-56); no.194-210; no.197-205; no.201-224 1955-1956; 220-231 (1956-57); no.207-228 1956-57; 232-253 (1957-58); no.211-224; no.225-245; no.230-235; no.239-256 1957-58; 254-270 (1958-59); no.246-260; no.258-261; no.261-279; no.263-278 1959; 271-285 (1959-60); 299-310 (1960); 286-298 (1960); no.280-283; no.280-284; no.284; no.285-293; no.286-293; no.294-299; no.295-299; no.300-304; no.301-315 1960-61; 317-329 (1961-62); no.305-310; no.311-312; no.313-316; no.316-321; no.317-322; no.323-334; no.323-334 1961-62; 330-339 (1962); no.335-340; no.335-341 1962; no.341-346; no.342-349 1963; 348-362 (1963-64); no.347-350; no.350-356; no.351-360; no.358-375 1963-64; 363-379 (1964-65); no.361-373; no.374-381; no.376-387 1964-65; 380-393 (1965); 394-411 (1965-67); no.382-394; no.390-397; no.395-404; no.398-408 1966-67; 412-424 (1967-68); no.405-412; no.409-418 1967-68; no.413-417; no.418-428; no.419-426 1968; no.421-430 1968; no.427-434 1968; 425-437 (1968-69); no.429-436; no.435-444 1968-69; 438-447 (1969); no.437-444; no.445-453; no.445-455 1969-71; 448-455 (1970-71); no.454-460; no.454-467 1970-1971; 101-102 (1971); 456-464 (1971); no.456 (1971); no.457-462 1971; no.461-469; no.463-469; no.466 1971; no.467 1971; 465-471 (1971-72); no.468 1972; no.468-475 1972; no.470-475; no.475 1972; 472-476 (1973-73); no.476-480; no.476-483 1973; 480-484 (1973-74); no.481-483; no.481-491; no.484-490 1974-1975; 485-491 (1974-76); no.484-493 1974-76; 492-496 (1976); no.491-496 1976; 497-500 (1976-77); 501-504 (1978); no.492-500; no.494; no.506-514 1979-1980; 512-516 (1980-81); 519-523