000  $anz n  2
000  $a주제어
001  $aKSH1998010735
005  $a20021015000000
008  $a980429 n azknnaabn          |a a|a    | 
150  $a결정 필터[結晶--]
450  $a광석 여파기[鑛石濾波器]
450  $a압전 여파기
450  $wr$i영어$acrystal filter
550  $wg$a여파기[濾波器]