F. Caldeira et al.,  "Classification of public administration complaints", in OpenAccess Series in Informatics, Cordeiro, J., Pereira, M. J., Rodrigues, N. F., and Pais, S., Ed., Covilhã, Schloss Dagstuhl- Leibniz-Zentrum fur Informatik GmbH, Dagstuhl Publishing, 2022, vol. 104