lucene index algorithm

https://web.archive.org/web/20130904073403/http://www.ibm.com/developerworks/library/wa-lucene/

http://lucene.apache.org/core/4_10_2/core/org/apache/lucene/codecs/lucene410/package-summary.html#package_description

http://www.slideshare.net/prasen.bea/lucece-indexing

http://www.slideshare.net/nitin_stephens/lucene-basics

http://www.slideshare.net/lucenerevolution/what-is-inaluceneagrandfinal