| 000 | 00493nam a22001697a 4500 | ||
|---|---|---|---|
| 008 | 230425b |||||||| |||| 00| 0 eng d | ||
| 040 |
_aNational Science Library _cNational Science Library |
||
| 080 |
_a519.725/.728 _bM2 |
||
| 100 |
_aBeker, Henry _97348 |
||
| 245 |
_aCipher systems: _bThe protection of communications |
||
| 260 |
_aLondon: _bNorthwood Books, _c1982 |
||
| 300 | _a421p. | ||
| 650 | _aComputer | ||
| 653 | _aCommunications | ||
| 700 | 1 | 0 | _aPiper, Fred |
| 942 |
_2udc _cBK |
||
| 999 |
_c22950 _d22950 |
||