The 46th state, Oklahoma, presents its unusual history with the online version of The Encyclopedia of Oklahoma History and Culture. The Encyclopedia was prepared by over 500 "university-based scholars and independent historians and scholars," and was a joint effort by The Oklahoma Historical Society and Oklahoma State University Library Electronic Publishing Center. Visitors can click on the "Table of Contents" link near the bottom of the homepage to "Browse Entries Alphabetically", "Browse Entries Chronologically", or "Browse Entries by Subject". Browsing via chronology introduces visitors to Oklahoma starting with the "Precontact Era", through the "Westward Expansion" and on to "Twentieth Century to Present". Subject categories include "African Americans", "Farming", "Military", and "Petroleum". When searching, visitors will be taken to the Electronic Publishing Center Search Page, so they will need to choose the specific collection, Encyclopedia of Oklahoma History and Culture, from the drop down box, to confine the search to the Encyclopedia.