00000nz  a2200000n  4500
001  KSH1998001194
005  19980429124941
008  980429 n azknn|abn          |a a|a    | 
150  ▼aPU(네트워크)▲
450  ▼wr▼i영어▼aphysical unit▲
550  ▼wg▼a시스템 네트워크 구조[--構造]▲
550  ▼aPU 2▲
550  ▼aPU 2.1▲
550  ▼aPU 4▲
550  ▼aPU 5▲