From the reviews: "This book presents a very good introduc- tion to combinatorics. It covers most aspects of enumeration and order theory,... It is divided into three parts. The first part presents the basic material on mappings and po- sets... The second part deals with enumeration ... Finally the third part treats of the order-theoretic aspects ... In the text examples are given and at the end of each chapter valuable notes, also very good selected exercises. They con- stitute an organic part of the book. This book can warmly be recommended first of all to students interested in combina- torics. A two semester course can also be based on it."