## 3 Dataset Analysis
### Sources  
Figure 5 places the spotlight on the top 19 most relevant journals. In the process of obtaining the chart below, an exclusion criterion was considered. Only the journals with at least 16 articles published around the area of natural language processing in social media research were included.  
As can be noticed, the foremost position is held by the popular journal _IEEE Access_, which recorded a significant value of 92 published articles in the analyzed area, followed closely by the _Journal of Medical Internet Research_ with 85 documents. For the entire list, please consult Figure 5.  
Figure 6 depicts the core sources by using Bradford's law, a popular theory which divides three distinct zones based on the significance of the sources. According to [PERSON]'s Law, the identified sources are divided into three main categories based on the number of published papers [33; 34]. If the proportion of the articles in each category would be one-third of all the articles, then the number of journals in each group would be proportional, with 1:\(n\):\(n^{2}\)[26; 33; 34]. The journals placed in the core (Zone 1) are very significant and highly cited, the journals in the center (Zone 2) are moderately significant, while the journals in the external zone (Zone 3) comprise a larger number of less significant journals.  
That being said, in the case of our analysis, the most significant and highly cited journals, found in Zone 1, are listed here in order: _IEEE Access_; _Journal of Medical Internet Research_; _Applied Sciences-Basel_; _International Journal of Advanced Computer Science and Applications; Multimedia Tools and Applications_; _Social Network Analysis and Mining_; _Expert Systems with Applications_; _Information Processing & Management_; _Sustainability_; _Information_; _IEEE Transactions on Computational Social Systems_; _JMIR Medical Informatics_; _Peer_] _Computer Science_; _International Journal of Environmental Research and Public Health_; _ACM Transactions on Asian and Low-Resource Language Information Processing; _Electronics_; _CMC-Computers_, _Materials & Continua_; _JMIR Public Health and Surveillance_; _Journal of Biomedical Informatics_; _Frontiers in Public Health_ (please see Figure 6).  
Figure 5: Top 19 most relevant journals.  
Figure 7 brings to the foreground the journals' impact based on the h-index, a metric that proves the significance of a source by measuring the total count of published articles in the studied area, which register H-citations. The leading position is held by the _Journal of Medical Internet Research_ with 20 citations. The second place is occupied by _IEEE Access_, which gathered 17 citations, followed closely by _Information Processing & Management_ with 15 citations. For the entire list, kindly refer to Figure 7.  
Furthermore, it is not surprising that the journals with substantial impact based on h-index analysis can also be found in Zone 1, delimited above using Bradford's law.  
Sources' production over time is captured in Figure 8. As anticipated, based on previous findings, the journals that mark the most pronounced growth are _Applied Sciences  
Figure 6: Bradford’s law on source clustering.  
Figure 7: Journals’ impact based on the h-index.