| 000 | 00324 a2200133 4500 | ||
|---|---|---|---|
| 020 | _a0749260513 | ||
| 082 |
_a621.382 _b621 |
||
| 090 |
_c13479 _d19838 |
||
| 245 | _aBlock Optical systems | ||
| 260 |
_aNorthampoton _bOpen University _c1990 _g1990 |
||
| 300 |
_a84p. _c29cm |
||
| 650 | _aCommunications engineering | ||
| 942 | _cL | ||
| 999 |
_c41810 _d41810 |
||