**2.2 Second phase (selection and localization of databases - relational database model - entity-relationship model of the databases)**

The location and selection of databases will be done, where the search for articles with the subject of interest will be carried out.

We will use a relational database model and an entity-relationship model to guarantee the referential entity of which the databases and the articles are part.

The Relational Model Relationship refers to the entities and their respective relationships with the other entities; therefore, it allows referential integrity to take place [9].

The Entity-Relationship Model consists of representing descriptively1 and through a diagram the information system, formalizing all the storage structure of the database (**Figure 1**) [9].

#### **Figure 1.**

*Model entity general relationship model of the systematic review of the literature on a particular topic. Source: Taken and adapted from the book Relational Database Programming.*

*Artificial Intelligence Starts the Big Bang of Modern Medicine and Surgery DOI: http://dx.doi.org/10.5772/intechopen.112057*

Inclusion and exclusion criteria will be applied to guarantee the following good selection of articles.
