The evolution and impact of code smells: A case study of two open source systems. - Steffen M. Olbrich; Daniela S. Cruzes; Victor R. Basili; Nico Zazworka (ESEM, 2009)

Are all code smells harmful? A study of God Classes and Brain Classes in the evolution of three open source systems. - Steffen M. Olbrich; Daniela S. Cruzes; Dag I. K. Sjøberg (ICSM, 2010)