1. Teachers and students of the school or personnel of the research institute should first search the collection catalogue of their own units to determine whether their own units have electronic versions or printing brushes, which can be solved without leaving their units.

If you don't have a collection, you can search some free databases and search engines, such as GOOGLE and HIGHWARE. If you really can't find it, you can ask for help from the document delivery service of your library.

2. Social workers can search some free databases and search engines, such as GOOGLE and HIGHWARE. At the same time, you can also go to some professional forums for help, such as small wooden worms. At the same time, you can also register a document delivery account in some large document collection institutions and pay for the documents. Very convenient.

These methods must first learn the retrieval methods of each database.