Daniela Bianucci Gianpiero Cattaneo Davide Ciucci Entropies and Co-entropies for Incomplete Information Systems. 84-92 2007 conf/rskt/2007 RSKT http://dx.doi.org/10.1007/978-3-540-72458-2_10 db/conf/rskt/rskt2007.html#BianucciCC07