1. AllegroGraph. AllegroGraph website, http://www.franz.com/agraph/ (last retrieved in May 2010)
2. Apache Lucene (September 2008), Lucene website, http://lucene.apache.org/
3. Bader, D., Feo, J., Gilbert, J., Kepner, J., Koetser, D., Loh, E., Madduri, K., Mann, B., Meuse, T., Robinson, E.: HPC Scalable Graph Analysis Benchmark v1.0. HPC Graph Analysis (February 2009)
4. Bader, D., Madduri, K.: Parallel algorithms for evaluating centrality indices in real-world networks. In: ICPP, pp. 539–550 (2006)
5. BerkeleyDB. BerkeleyDB website, http://www.oracle.com/database/berkeley-db/index.html (last retrieved in March 2010)