Eulalia Szmidt Janusz Kacprzyk Atanassov's Intuitionistic Fuzzy Sets as a Promising Tool for Extended Fuzzy Decision Making Models. 335-355 2008 Fuzzy Sets and Their Extensions: Representation, Aggregation and Models http://dx.doi.org/10.1007/978-3-540-73723-0_17 series/sfsc/2008-220 db/series/sfsc/sfsc220.html#SzmidtK08