Earth history field trip for high school science teachers.
APA Citation
Illinois State Geological Survey. (194749). Earth history field trip for high school science teachers. [Urbana, Ill.? : Illinois State Geological Survey.
MLA Citation
Illinois State Geological Survey. Earth History Field Trip for High School Science Teachers. [Urbana, Ill.? : Illinois State Geological Survey, 194749.
Warning: These citations may not always be complete (especially for serials).