**2. Materials and Methods**

There are two complementary methods used in this research. First is the SLR variation with queries (Figure 1, path no. 1), and it is used to explore the scientific database to determine GJ's definition consistency by the queries syntax. The second method is the search results analysis performed in the Scopus database online to identify the most cited publications and most contributing authors (Figure 1, path no. 2). The first method results are analyzed in VOSviewer in form of bibliometric maps. The second method is the analysis of the results in Scopus and is a development of the first used in this paper method, the SLR results method. Therefore, this section is divided into two subchapters.

**Figure 1.** Methods and stages of the research. Source: Authors' elaboration.

The stages of the research covered 5 months of the bibliometric study. In the first period, based on the initial query formulation and calibration, observations have been made. In this stage, Supplementary Materials File S1 has been constructed. The conclusions and remarks have been gathered after all stages were completed and have been introduced into proper sections of this paper.
