In view of the coming plebiscite in the Saar Basin, many students of international affairs will want to study this book. Miss Wambaugh is an authority on the subject, and this new study is really the continuation of an earlier one which appeared in 1920. Since that time the author has been connected with the League as an expert, and also had a hand in the Tacna-Arica problem. Her account of a long list of plebiscites and attempted plebiscites is detailed and heavily documented. The whole second volume is devoted to documents. The work is not only valuable, but interesting.