1 INTRODUCTION  
2 PRELIMINARIES  
3 PAPER COLLECTION METHODOLOGY AND RESULT  
4 LITERATURE OF EMPIRICAL STUDY ON ADS TESTING  
5 LITERATURE OF TECHNIQUES ON MODULE-LEVEL ADS TESTING  
6 LITERATURE OF TECHNIQUES ON SYSTEM-LEVEL ADS TESTING  
7 STATISTICS AND ANALYSIS OF LITERATURE  
8 CHALLENGES AND OPPORTUNITIES  
9 CONCLUSION