|
GB240362A
|
|
Process of increasing the refraction and hardness of imitation precious stones
|
|
DE442916C
|
|
Process for the production of particularly heat-resistant products from any zirconium ores
|
|
GB223573A
|
|
Improvements relating to refractory products and their manufacture
|
|
GB224214A
|
|
Refractory cement with a base of zirconium ore
|
|
GB223572A
|
|
Process for the commercial production of pure oxide of zirconium
|
|
US1602273A
|
|
Refractory products and their manufacture
|
|
US1565472A
|
|
Refractory cement with a base of zirconium ore
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