Most genealogists make ample use of census records, vital records, wills and deeds, but they overlook periodicals — treasure troves of transcribed records, carefully researched family histories and genealogical case studies. The thousands of genealogical and historical periodicals published in the last two centuries just might mention your ancestors. And the Periodical Source Index (PERSI), an enormous subject index created by the Allen County Public Library (ACPL) <www.acpl.lib.in.us> in Fort Wayne, Ind., helps you find those articles in a flash.

The ACPL first published PERSI in a series of printed volumes. CD-ROM and online versions followed, making the index much more affordable and easier to use. Now the ACPL is collaborating with online-content provider ProQuest to make PERSI an even more valuable tool. ProQuest recently released a brand-new version of PERSI on HeritageQuest Online <www.heritagequestonline.com>, an extremely useful collection of US census records and 25,000-plus family and local history books, which genealogists can access at subscribing libraries. The PERSI database contains more than 1.6 million citations to articles in 6,300-plus titles published in English or in French (Canadian periodicals only) and daring back to 1800. The index is updated annually, and ProQuest will add about 70,000 new citations by early 2005.

If you've searched PERSI in the past, you probably wonder what's special about HeritageQuest Online's version. After all, Ancestry.com <www.ancestry.com > already offers an online version of PERSI as part of its US Records Collection ($12.95 per month, $79.95 per year), which individual researchers can access from home — not just through subscribing institutions. To begin with, searches on HeritageQuest Online turn up more spelling variations, including plurals. The really exciting part will come later this year, when HeritageQuest Online begins linking PERSI citations to digital images of the articles. You'll be able to view the original articles right on your computer screen, instead of having to send for photocopies from the ACPL. Initially, more than 196,000 articles — encompassing 1.2 million pages — gradually will be linked to citations. That's about 12 percent of the articles indexed in PERSI, and more articles will follow. Libraries will have to subscribe to a premium service in order to get access to the digital images.