Perhaps you should try some spelling variations:
"bo sach ma thuat ung dung tren marketing" » "bo sach ma thuat ung dung trong marketing", "bo sach ma thuat ung dung trinh marketing", "bo sach ma thuat ung dung thien marketing", "bo sach ma thuat dung dung tren marketing", "bo sach ma thuat hung dung tren marketing", "bo sach ma thuat xung dung tren marketing", "bo sach ma thuat ung dung trung marketing", "bo sach my thuat ung dung tren marketing", "bo sach va thuat ung dung tren marketing", "bo sach mi thuat ung dung tren marketing", "co sach ma thuat ung dung tren marketing", "hoc sach ma thuat ung dung tren marketing", "bo sach mau thuat ung dung tren marketing", "bo sach xa thuat ung dung tren marketing", "bo sach ha thuat ung dung tren marketing"
"bo sach ky thuat song dung dat marketing" » "bo sach ky thuat song dung tac marketing", "bo sach ky thuat song dung van marketing", "bo sach ky thuat song dung thuat marketing", "bo sach ky thuat song duong dat marketing", "bo sach ky thuat cong dung dat marketing", "bo sach ky thuat song dong dat marketing", "bo sach ky thuat song dung va marketing", "bo sach ky thuat song dung tai marketing", "co sach ky thuat song dung dat marketing", "hoc sach ky thuat song dung dat marketing", "bo sac ky thuat song dung dat marketing", "bo sach y thuat song dung dat marketing", "bo sach ty thuat song dung dat 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: (("bo sach ma thuat ung dung tren marketing") OR ("bo sach ky thuat song dung dat marketing"))~.
• Removing quotes may allow a broader search: (( bo sach ma thuat ung dung tren marketing ) or ( bo sach ky thuat song dung dat marketing ))~.
• Adding a wildcard symbol may retrieve word variants: (("bo sach ma thuat ung dung tren marketing") or ("bo sach ky thuat song dung dat marketing"))*.