The work "The Application of Competition Rules in Natural Gas Supply Contracts - Particularly the Example of Take or Pay Clauses - EU Natural Gas Market: Quo Vadis? A Long Term Conundrum of Long Term Contracts..." examines the existing theoretical and empirical research regarding long-term natural gas supply contracts. It emphasizes the importance of take or pay clauses regardless of receipt, their interdependence with supply security, and their economic fundamentals as mechanisms for financing energy projects. Since the liberalization of energy markets and the announcement of the Commission's inquiry into the energy sector, the portfolio of long-term supply contracts of former established operators has become a priority for review by the European Commission and national competition authorities in order to balance their anti-competitive effects with a potential increase in efficiency.