Table of contents6.1 Circulations6.2 Flows in Networks6.3 Group-Valued Flows6.4 k-Flows for Small k6.5 Flow-Colouring Duality6.6 Tutte’s Flow Conjectures6.1 Circulations 6.2 Flows in Networks 6.3 Group-Valued Flows 6.4 k-Flows for Small k 6.5 Flow-Colouring Duality 6.6 Tutte’s Flow Conjectures