1. Available at:
http://arthursclassicnovels.com/
2. Available at:
http://www.cs.wisc.edu/niagara/data.html
3. Available at:
http://research.imb.uq.edu.au/rnadb/
4. Available at:
http://www.assortedthoughts.com/downloads.php
5. Available at:
http://www.ibiblio.org/bosak/