Periodicals Index Online (PIO) indexes the articles in over 4,000 periodicals in the humanities and social sciences from their first issues to 1995.   As of December 2005, over 500 journal titles are at least partially available in full text in the complementary database, Periodicals Archive Online (PAO).  The focus is on 20th century periodicals.  However, periodicals in the 20th century that extend back into the 17th, 18th, & 19th centuries are indexed from their earliest volumes.  The scope is worldwide and includes journals in English, German, Italian, French, Spanish, and other Western languages.  (GB)