Hierarchical organisation in complex networksHierarchical organisation is an ubiquitous feature of a large variety of systems studied in natural- and social sciences. One of the related key problems is quantifying the importance of hierarchical organisation in the structure of the network representing the interactions or connections between the fundamental units of the studied system. In the first part of the talk I shall overview a few different hierarchy measures aimed at grasping the signs of hierarchy in a network in a quantitative way. As an interesting application, in the second part of the talk I will show how we can apply the concept of hierarchy and hierarchy measures for providing a novel type of ranking between scientific journals.