Groove Formations, E.g. Run-in Groove, Run-out Groove {g11b 3/72} Patents (Class G9B/3.107)

Cross-Reference Art Collections

Multiple output tracks, e.g. binaural stereophonic {g11b 3/74} (Class G9B/3.108)
Forming part of cinematograph films {g11b 3/76} (Class G9B/3.109)

There are no patents to show for this class.