This book is aimed at the level of bright high school students or beginning college students. The problems were taken from a multiplicity of sources, including Mathematical Olympiads and other competitions, especially from Eastern Europe. The sources of individual problems are not acknowledged. For example, this reviewer's book Polyominoes is "Reference 1", and is specially recommended to those interested in further study of certain types of tiling questions; but individual results and problems taken from it are not identified as such. The translation is generally excellent, although "fields" is not the best word to refer to the cells, or squares, of a chessboard or other rectangular array.
This book would be ideal for preparing high school students for competitions such as the Mathematical Olympiads, and is an outstanding source of classroom and homework problems for college students taking a course in combinatorics. This book could be used as an auxiliary text, but probably not as the main text, in such a course.