*3.2. Bibliographic Analysis*

To identify the main research themes in circular economy and sustainability-oriented innovation, we combined the bibliography of these documents with VOSviewer 1.6.18 software. All articles were analyzed by linking a minimum of three articles per cluster. The cluster network is shown in detail in Figure 5.

The results of the network visualization show that there were seven main clusters related to the two research topics. Some of the relevant items in each cluster are described as follows.

**Figure 5.** Network visualization of circular economy and sustainability-oriented innovation.
