1, print search
The king of encyclopedias and reference books. It is a complete reference book summarizing all kinds of human knowledge or a certain kind of knowledge, and it is a collection of knowledge. It is the product of collecting, concentrating and organizing existing human knowledge. Encyclopedias are generally arranged in alphabetical order according to the items (entries) and have corresponding indexes, which are convenient for quick search.
2. Computer retrieval
EI, founded in 1884, is a well-known comprehensive retrieval tool for engineering technology published by engineering information company, and the collected literature covers almost all fields of engineering technology. For example: electric power, electrician, electronics, automatic control, mining and metallurgy, metal technology, machinery manufacturing, civil engineering, water conservancy and so on.
3. Software retrieval
In the era of electronic resources, people have been able to easily retrieve documents from various databases. In order to retrieve the required literature, researchers have to log in to different databases for retrieval, which is cumbersome. Therefore, the literature retrieval software came into being. At present, many literature management software at home and abroad provide retrieval function. The more integrated databases, the more convenient it is to use. Extended data
Software retrieval classification:
1, according to the means of literature retrieval is divided into the following two kinds:
(1) manual retrieval;
(2) Computer retrieval. ?
2, according to the content of the search results are divided into the following three kinds:
(1) Data retrieval: retrieval based on data in literature. For example, find the resistance of a certain material and the melting point of a certain metal;
(2) fact retrieval: according to the facts in the literature, retrieve the time, place or process of an event; For example, find out that Lu Xun was born in a certain year;
(3) Literature retrieval: retrieval with the original literature as the retrieval object.
Baidu Encyclopedia-Literature Retrieval