Perhaps you should try some spelling variations:
"bo sach ki thuat dung cong trinh marketing" » "bo sach ki thuat dung cong tri marketing", "bo sach ki thuat hung cong trinh marketing", "bo sach ki thuat ung cong trinh marketing", "bo sach ki thuat xung cong trinh marketing", "bo sach ky thuat dung cong trinh marketing", "hoc sach ki thuat dung cong trinh marketing", "bo sach kinh thuat dung cong trinh marketing", "bo sach bai thuat dung cong trinh marketing", "bo sach kem thuat dung cong trinh marketing"
"co sach my thuat dung dung trong marketing" » "co sach my thuat dung dung tri marketing", "co sach my thuat dung dung tvqg marketing", "co sach my thuat hung dung trong marketing", "co sach my thuat ung dung trong marketing", "co sach my thuat xung dung trong marketing", "co sach my thuat dung ung trong marketing", "co sach my thuat dung dong trong marketing", "co sach ky thuat dung dung trong marketing", "co sach va thuat dung dung trong marketing", "cuon sach my thuat dung dung trong marketing", "hoc sach my thuat dung dung trong marketing", "co sach y thuat dung dung trong marketing", "co sach ty thuat dung dung trong marketing", "co sach mau thuat dung dung trong marketing"

Try widening your search to All Fields.

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

• Performing a fuzzy search may retrieve terms with similar spellings: (("co sach my thuat dung dung trong marketing") or ("bo sach ki thuat dung cong trinh marketing"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("co sach my thuat dung dung trong marketing") OR ("bo sach ki thuat dung cong trinh marketing")).
• Removing quotes may allow a broader search: (( co sach my thuat dung dung trong marketing ) or ( bo sach ki thuat dung cong trinh marketing )).
• Adding a wildcard symbol may retrieve word variants: (("co sach my thuat dung dung trong marketing") or ("bo sach ki thuat dung cong trinh marketing"))*.