Social network analysis (SNA) is defined as the process of social structures research using networks and graph theory (branch of mathematics).
It describes networks in terms of nodes (or points) and edges (ties or links). In real life, nodes are typically referred to individual actors, people, or things within the network, while edges are used to outline relationships or interactions among them. Social networks do not apply to people only, but to all interactions made by humans, from personal and business networks, social media, knowledge networks, and cuisines, as far as to disease transmission. Dr. Grgić has specialized in knowledge networks, as he created knowledge graphs for all countries of the world, which were published in his book World of Skills. (link na 3.1.)
He has also presented his research on knowledge graphs through an exhibition “European Knowledge Graphs”, by creating large size posters of the highest globally ranked skills of EU Member States. You can see the whole exhibition here: