http://book.klll.cc/ebooks/subject/36912.opds 2025-11-18T08:16:59Z Books about Petrology -- Illinois Free eBooks since 1971. Project Gutenberg https://book.klll.cc webmaster@gutenberg.org https://book.klll.cc/gutenberg/favicon.ico 25 1 2025-11-18T08:16:59Z https://book.klll.cc/ebooks/66308.opds Guide to Rocks and Minerals of Illinois Illinois State Geological Survey