Then it described the chinese patent classification, Chinese patent retrieval system and the method how to use them.

归纳了我国专利分类体系和专利文献的检索工具。

youdao

Then it described the chinese patent classification, Chinese patent retrieval system and the method how to use them.

归纳了我国专利分类体系和专利文献的检索工具。

youdao