I've been searching on literature on approximation algorithms in the context of network-flow problems (optimization) to finish my bachelor degree.
However, I have been looking in several well-known algorithm books but, I haven't yet found something. Most books don't go beyond Ford-Fulkerson and/or Edmond-Karp in respect to network-flow problems, and the sections explaining approximation algorithms discuss some algorithms not relating to network-flow optimization.
Could someone point me towards appropriate literature? I prefer books instead of papers.