The University of Michigan Digital Library Test Collection includes the two volume set of the Report of the Debates and Proceedings of the Convention for the Revision of the Constitution of the State of Indiana 1850 which are now out-of-print. These volumes are fully searchable online and may be purchased (print on demand) via the University of Michigan "Scholarly Publishing Office". (The pages take some time to load.)
Several other Indiana Historical Bureau-published out-of-print books are available at HeritageQuest™ online. HeritageQuest™ online is a subscription service available for a fee. The Indiana State Library subscribes and access is available from the State Library public computers while in the State Library building. To find a particular book, choose "Search Books" and then "Publications - browse magazines or books". Other books about Indiana may be found in this resource.
The Indiana Centennial, 1916: A Record of the Celebration of the One Hundredth Anniversary of Indiana's Admission to Statehood
A Sergeant's Diary in the World War: The Diary of an Enlisted Member of the 150th Field Artillery (Forty-Second [Rainbow] Division) October 27, 1917 to August 7, 1919
Indiana Boundaries: Territory, State, and County
The John Tipton Papers, Vol. 1, 1809-1827
The John Tipton Papers, Vol. 2, 1828-1833
The John Tipton Papers, Vol. 3, 1834-1839
Readings in Indiana History (still in print)
Indiana in the War of the Rebellion: Report of the Adjutant General