This text contains over three hundred specific open questions on various
topics in additive combinatorics, each placed in context by reviewing all
relevant results. While the primary purpose is to provide an ample supply of
problems for student research, it is hopefully also useful for a wider
audience. It is the author's intention to keep the material current, thus all
feedback and updates are greatly appreciated.Comment: This August 2017 version incorporates feedback and updates from
  several colleague