@article{TiB:98,
   author    = {A. L. Tits and V. Balakrishnan},
   title     = {Small-$\mu$ Theorems with Frequency-Dependent Uncertainty Bounds},
   journal   = {Mathematics of Control, Signals, and Systems},
   year      = {1998},
   volume    = {11},
   number    = {3},
   pages     = {220-243}
}