Contact the NH State Library: tel:603-271-2144 or Ask a Librarian.
The New Hampshire State Library catalogs state publications and classifies them using the Dewey system. Records for most items (except ephemera) are loaded into OCLC.
The GODORT State Agency Databases New Hampshire Guide provides an annotated list of state government agency resources which includes libraries, catalogs, directories and digital collections. These are excellent resources for cataloging and authority work.