Igor Djurovic Srdjan Stankovic Ljubisa A. Stankovic Radovan D. Stojanovic Local frequency estimation based on the Wigner distribution. 736-739 2001 ICIP (3) http://dx.doi.org/10.1109/ICIP.2001.958224 db/conf/icip/icip2001-3.html#DjurovicSSS01