2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/127374I propose to sharpen the index h, proposed by Hirsch as a useful index to characterize the scientific output of a researcher, by excluding the self-citations. Performing a self-experiment and also analyzing two anonymous data sets, it is shown that self-citations can significantly reduce the $h$ index in contrast to Hirsch's expectations. This result is confirmed by an analysis of 13 further data sets.6 pages, 6 figures, accepted for publication in EPL, more data sets investigated and more references added in comparison with previous versionPhysics and Societytext