Subclass Subgroup Patent
C03B 33/0222 11091383
  37/01413 11091384
  37/02727 11091385
C03C 8/04 11091386
  8/08 11091387
  10/0009 11091388
  17/32 11091389
  17/366 11091390
  17/3681 11091391
  21/002 11091392