In the development of digital publishing, the electronization of academic publishing started earlier, and many mature products-academic resource database have been formed. This appendix sorts out the commonly used Chinese academic full texts for reference. The following four points are particularly explained:

1. Most of the data below are commercial databases, and you usually need to pay a subscription to see the full text. Some databases open a small amount of content for Internet users to access for free. Most databases support various payment instructions of individual users.

2. At present, there are many kinds and bibliographies of academic full-text databases in China. The following are only commonly used databases, classified by literature type or subject; But everyone's habits and preferences are different, and what kind of database is commonly used is a matter of opinion;

3. Because the electronic database is dynamic, the variety, year, total literature and other data mentioned in the introduction below were accessed from various database pages on July 10.

With the electronization of academic documents, readers' reading habits have changed. The investigation of readers' behavior in Tsinghua University Library shows that electronic resources have become an indispensable means of scientific research. In the era of network environment and digital resources, readers spend less time searching for documents and more time reading them. It is more convenient to retrieve documents, but the technical requirements for searching documents are higher; There are more ways to query and read documents, more documents are found, and the number of documents read by readers has increased.