The Periodical Source Index, or PERSI, is a large subject index of periodical articles that are historical or genealogy related. It was created by the Allen County Public Library in Fort Wayne, Indiana. The easiest way to access the index is with HeritageQuest Online, available from home through most public libraries. The ordering form for photo copies of articles and additional details are available at this link. I ordered the maximum of 6 copies with the my first form and the total cost was $9.10.