The most lengthy and authoritative contemporary overview of Shi'ism; a commonly-assigned college textbook. Includes biographies of prominent historical figures. Not yet formatted.
See also a 1/4-length summary of this book, momen_introduction_shii_sumary, and a short encyclopedia version, momen_encyclopedia_shii_islam.
Documents posted between 2003-2012 had slightly different URLs and can be found in archive.org with addresses like bahai-library.com/?file=momen_introduction_shii_islam.
Documents posted prior to October 2003 were at bahai-library.org [archive.org] and had completely different URLs.