@article{MET_1978__25_175752,
     author = {A.B. El-Sayed},
     title = {Cascaded {Channels} and the {Equivocation} {Inequality.}},
     journal = {Metrika},
     pages = {193--208},
     year = {1978},
     volume = {25},
     zbl = {0391.94010},
     url = {http://geodesic.mathdoc.fr/item/MET_1978__25_175752/}
}