@article{TUW-103113, author = {Hlawatsch, Franz and Papandreou-Suppappola, A. and Boudreaux-Bartels, G.F.}, title = {The hyperbolic class of quadratic time-frequency representations - part II: Subclasses, intersection with the affine and power classes, regularity, and unitarity}, journal = {IEEE Transactions on Signal Processing}, year = {1997}, volume = {vol. 45}, number = {no. 2}, pages = {303--315}, url = {http://publik.tuwien.ac.at/files/pub-et_3347.pdf} }