Perhaps you should try some spelling variations:
"co sach ky thuat cung dung trong marketing" » "co sach ky thuat cung dung tri marketing", "co sach ky thuat cung dung tvqg marketing", "co sach ky thuat chung dung trong marketing", "co sach ky thuat cong dung trong marketing", "co sach ky thuat dung dung trong marketing", "co sach ky thuat cuong dung trong marketing", "co sach ky thuat ung dung trong marketing", "co sach ky thuat cung ung trong marketing", "bo sach ky thuat cung dung trong marketing", "cuon sach ky thuat cung dung trong marketing", "hoc sach ky thuat cung dung trong marketing", "co sac ky thuat cung dung trong marketing", "co sach y thuat cung dung trong marketing", "co sach ty thuat cung dung trong marketing"
"co chu ky thuat hung dung tren marketing" » "co chu ky thuat hung dung trinh marketing", "co chu ky thuat hung dung thien marketing", "co chu ky thuat hung dung tri marketing", "co chu ky thuat dung dung tren marketing", "co chu ky thuat ung dung tren marketing", "co chu ky thuat xung dung tren marketing", "co chu ky thuat nhung dung tren marketing", "co chu ky thuat phung dung tren marketing", "co chu ky thuat hung dung trung marketing", "cho chu ky thuat hung dung tren marketing", "cao chu ky thuat hung dung tren marketing", "co che ky thuat hung dung tren marketing"

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

• If you are trying to use Boolean operators, they must be ALL CAPS: (("co sach ky thuat cung dung trong marketing") OR ("co chu ky thuat hung dung tren marketing"))~.
• Removing quotes may allow a broader search: (( co sach ky thuat cung dung trong marketing ) or ( co chu ky thuat hung dung tren marketing ))~.
• Adding a wildcard symbol may retrieve word variants: (("co sach ky thuat cung dung trong marketing") or ("co chu ky thuat hung dung tren marketing"))*.