Martin Aigner, Combinatorial Theory (Repost)

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.