Kessler, G. C.
ISDN concepts, facilities, and services - New York McGraw Hill 1991 - xvi, 302p. - McGraw-Hill communications series .
0-07-112662-7
ISDN concepts, facilities, and services - New York McGraw Hill 1991 - xvi, 302p. - McGraw-Hill communications series .
0-07-112662-7