• A New Framework for Join Product Skew. Foto Afrati, Viktor Kyritsis, Paraskevas Lekeas and Dora Souliou. Technical Report, Apr., 2010, Applied Math Department, University of Crete, Greece. [Accepted for publication, LNCS, Springer, 2011 (A short version appeared in Third International Workshop on Resource Discovery (RED), iiWAS2010, November 5, 2010, Paris, France)]

• Answering Aggregation Queries on Hierarchical Web Sites Using Adaptive Sampling. Foto Afrati, Paraskevas Lekeas, and Chen Li. Technical Report, UCI ICS, August 2005. [A short version appears in CIKM 2005, 31st October - 5th November, 2005 Bremen, Germany. Full version appears in Data and Knowledge Engineering, Elsevier, Vol. 64, Issue 2, February 2008, Pages 462-490.]