Integer flows in graphs. Group and modular flows, basic properties.
Tutte's conjectures on nowhere-zero flows, known partial results. The classical characterization of graphs with k disjoint spanning trees.
The cycle double cover conjecture, relations to flows. Compatible decompositions of Eulerian graphs.
Tensions, the tension-flow duality. Flow-continuous and cycle-continuous maps, the Petersen coloring conjecture.
Introduction to nowhere zero flows and cycle covers of graphs and matroids.