000 00271 a2200073 4500
245 0 _aITU World Telecommunication Forum :
_bTechnical Symposium /
_c.
_nPart 2 vol.3
710 2 _aInternational Telecommunication Union.
_eWydawca
_4pbl
260 _aGeneva :
_bITU,
_c1987.
300 _a201 s.:
_bil.;
_c30 cm.
999 _c6877
_d6877