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| 300 | |a 1 sound reel tape : |b analog. |
| 300 | |a 1 sound cassette: |b analog. |
| 300 | |a 3 videocassettes : |b silent ; |c 1/2 in. |
| 300 | |a 5 sound discs : |b digital ; |c 4 3/4 in. |
| 300 | |a 9 film reels : |c 16 mm. |
EXAMPLE for DVDs:
300 $a4 videodiscs : $bsound, color ; $c4 ¾ in.
See also the Library of Congress for more examples:
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