Q: When is the book going to be published?
A: Sometime late summer 2019 or early fall 2019.
Q: Why another book on network flow?
A: I thought there were enough interesting network flow algorithms that did not have a textbook presentation (such as the Goldberg-Rao algorithm, and some of the multicommodity flow algorithms) that I wanted a book that would cover these algorithms. I also wanted a book that put generalized flow on the same footing as more standard flow topics such as max flow and minimum-cost flow. It also gave me the opportunity to add in some coverage on the recent work on electrical flows.

Q: What is the cover image?
A: It's a sakia, a water lifting device.