S. Kontamwar, P. Warbhe, and P. Dubey. International Journal on Recent and Innovation Trends in Computing and Communication, 3 (4):
2471--2473(April 2015)
R. Agrawal, and R. Srikant. Proceedings of the 20th international conference on Very Large Data Bases (VLDB'94), page 478--499. Morgan Kaufmann, (September 1994)