**3. Conceptual evolution of COVID-19: a bibliometric analysis**

#### **3.1 Data sources and collection**

This chapter selects the Scopus collection as the main data source (https:// www.scopus.com/). The search terms are the followings: COVID-19 and economy or COVID-19 and environment or climate change or COVID-19 and public health. The period analyzed was from 2019 to 2021. All languages have been considered. Initially, the Scopus database considered various type of documents, but only original articles were included in the present analysis. 7806 documents were selected for the analysis but finally limited to the first 2000 due to the limitation of the Scopus importation in BibTex file and imported into Bibliometrix and Biblioshiny.

#### **3.2 Research software**

Bibliometrix and Biblioshiny open-source packages are used from the R language environment. Bibliometrix allows completing the full process of scientific literature analysis and data process. Biblioshiny captures the core Bibliometrix code and creates an online data analysis framework [3]. Biblioshiny enables users to perform pertinent bibliometric and visual analysis based on an interactive web interface.

Network analysis and mapping using the Bibliometrix and the Biblioshiny packages, the research allows showing bibliometric indicators on COVID-19 such as publication volume in number of articles, citation count, and keywords. Then, the article presents figures and maps such as a citation network diagram, thematic evolution map, and an international collaboration network map to identify research hotspots, research status and the dynamics of COVID.

#### **3.3 Results of most relevant sources**

The journal that published most articles about COVID-19 during the period were presented in **Figure 2**. International Journal of Environmental Research and Public Health was the journal that published the highest number of articles on COVID-19 during the period (72 articles). Frontiers in Public Health was the second leading journal with 63. The journal Frontiers in Public Health published 34 articles and the Journal of Medical Internet Research 23 articles. International Journal of Environmental Research and Public Health is the source with the higher impact, with an h index of 12.

#### **3.4 Mapping the scientific collaboration**

A map shown in **Figure 3** identifies the country collaboration of the main producing countries. Two countries hold a connection line indicating the status

**Figure 2.** *Most relevant sources in the field of COVID-19.*

**Figure 3.** *Country collaboration map.*

of collaboration among them. The scale of cooperation is represented through the thickness of the line. The United States, China, Australia, Western European countries showed deepened cooperation and exchange among scholars.

**Figure 4** shows a co-citation analysis, with each box representing an article in the COVID literature. The size of the box indicates the volume of the citation (the larger the box, the more author's documents are cited) and the proximity of the boxes indicates a close relationship between the co-cited documents.

### **3.5 Analysis of keywords and co-keywords**

**Figure 5** illustrates the keyword co-occurrence network. The number of occurrences of the keywords is represented through the dimension of the box. When authors' keywords were more co-selected in the COVID-19 literature,

*The Economic, Climate Change and Public Health Edges of the Geopolitics of COVID-19… DOI: http://dx.doi.org/10.5772/intechopen.96797*

**Figure 4.** *Co-citation network.*

the box is larger. The topic similarity and its relative strength is represented through the distance between the elements of individual pairs. Different box colors were assigned to individual clusters. A network of three distinct clusters are highlighted in **Figure 4**, representing individual subfields in COVID-19 research.
