Improving the performance and functionality of Mondrian open-source OLAP systems. - Pablo Sendín-Raña; Francisco J. González-Castaño; Enrique Pérez-Barros; Pedro S. Rodríguez-Hernández; Felipe J. Gil-Castiñeira; José M. Pousada Carballo (Softw. Pract. Exp., 2009)