Perhaps you should try some spelling variations:
hieu cua » hieu qua, dieu cua, bieu cua
cau tren » cu tren, dau tren, ca tren
te sac » te sach, te cac, te san
sac ky » cac ky, sai ky
luc va » duc va, tuc va
loc va » hoc va
dan vi » doan vi, don vi, gan vi
dan va » doan va, dan ca, ban va

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sac ky nang x ho. hieu cua cac ((luc va) or (loc va)) ((dan vi) or (dan va)) cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sac ky nang x ho. hieu cua cac ((luc va) OR (loc va)) ((dan vi) OR (dan va)) cau tren.
• Adding a wildcard symbol may retrieve word variants: te sac ky nang x ho. hieu cua cac ((luc va) or (loc va)) ((dan vi) or (dan va)) cau tren*.