Web Page Classification with an Ant Colony Algorithm. - Nicholas Holden; Alex Alves Freitas (PPSN, 2004)

A hybrid particle swarm/ant colony algorithm for the classification of hierarchical biological data. - Nicholas Holden; Alex Alves Freitas (SIS, 2005)

Communication, Leadership, Publicity and Group Formation in Particle Swarms. - Riccardo Poli; William B. Langdon; Paul Marrow; James Kennedy; Maurice Clerc; Daniel Bratton; Nicholas Holden (ANTS Workshop, 2006)

A hybrid PSO/ACO algorithm for classification. - Nicholas Holden; Alex Alves Freitas (GECCO (Companion), 2007)

Comparing Several Approaches for Hierarchical Classification of Proteins with Decision Trees. - Eduardo P. Costa; Ana Carolina Lorena; André Carlos Ponce de Leon Ferreira de Carvalho; Alex Alves Freitas; Nicholas Holden (BSB, 2007)

Improving the Performance of Hierarchical Classification with Swarm Intelligence. - Nicholas Holden; Alex Alves Freitas (EvoBIO, 2008)

Improving the Hierarchical Classification of Protein Functions With Swarm Intellegence. - Nicholas Holden (2008)

Hierarchical classification of protein function with ensembles of rules and particle swarm optimisation. - Nicholas Holden; Alex Alves Freitas (Soft Comput., 2009)