Perhaps you should try some spelling variations:
"co sach va thich ung dung sai marketing" » "co sach va thich ung dung tri marketing", "co sach va thich ung dung tac marketing", "co sach va thich ung dung van marketing", "co sach va thich anh dung sai marketing", "co sach va thich ngu dung sai marketing", "co sach va trinh ung dung sai marketing", "co sach va tich ung dung sai marketing", "co sach va tinh ung dung sai marketing", "co sach va thuc ung dung sai marketing", "co sach va thich ung dung tai marketing", "co sach va thich ung dung va marketing", "co sach va thich ung dung dat marketing", "cuon sach va thich ung dung sai marketing", "hoc sach va thich ung dung sai marketing", "co sach xa thich ung dung sai marketing", "co sach ha thich ung dung sai marketing", "co sach dao thich ung dung sai marketing"
"bo sach ki thuat ung dung doi marketing" » "bo sach ki thuat ung dung dong marketing", "bo sach ki thuat ung dung tri marketing", "bo sach ki thuat ung dung thi marketing", "bo sach ki thuat dung dung doi marketing", "bo sach ki thuat hung dung doi marketing", "bo sach ki thuat xung dung doi marketing", "bo sach ky thuat ung dung doi marketing", "bo sach ki thuat ung huong doi marketing", "bo sach ki thuat ung dung tai marketing", "bo sach ki thuat ung dung co marketing", "hoc sach ki thuat ung dung doi marketing", "bo sach kinh thuat ung dung doi marketing", "bo sach bai thuat ung dung doi marketing", "bo sach kem thuat ung dung doi marketing"

You may be able to get more results by adjusting your search query.

• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"co sach va thich ung dung sai marketing\") OR (\"bo sach ki thuat ung dung doi marketing\"))~".
• Removing quotes may allow a broader search: (( co sach va thich ung dung sai marketing ) OR ( bo sach ki thuat ung dung doi marketing ))~.
• Adding a wildcard symbol may retrieve word variants: (("co sach va thich ung dung sai marketing") OR ("bo sach ki thuat ung dung doi marketing"))*.