 As a contemporary teacher of Sun Tzu 's Art of War , Khoo has written over 26 books on business and management based on its principles such as : 
 As a contemporary teacher of Sun Tzu <a href='null_genetive' title='1'><mark>'s</mark></a>Art of War , Khoo <a href='been_done' title='2'><mark>has</mark></a> written over 26 books on business and management based on its principles such as : 
As a contemporary teacher of Sun Tzu  Art of War , Khoo done written over 26 books on business and management based on its principles such as :