“…In particular, the increasing consumption of natural gas within the European Union has led to an even sharper growth of the literature on this specific source of energy. Research focuses on a wide variety of topics such as broad regulatory aspects [11][12][13], security of supply and socio-economic risks [14,15], optimization models accounting for operational costs of the transmission network [16,17, and references therein] and network expansions [18][19][20][21].…”