APA (7th ed.) Citation

Illinois State Geological Survey. Directory of Illinois mineral producers. [publisher not identified].

Chicago Style (17th ed.) Citation

Illinois State Geological Survey. Directory of Illinois Mineral Producers. Urbana: [publisher not identified].

MLA (9th ed.) Citation

Illinois State Geological Survey. Directory of Illinois Mineral Producers. [publisher not identified].

Warning: These citations may not always be 100% accurate.