Subclass Subgroup Patent
C01B 3/384 11679977
  21/0641 11679978
  23/0063 11679979
  25/14 11679980
  32/168 11679981
  32/182 11679982
  32/192 11679983
  33/149 11679984
  33/182 11679985
  33/325 11679986
  39/023 11679987
C01C 1/0494 11679988
C01G 9/08 11679989
  23/053 11679990
  49/009 11679991
  53/006 11679992