Perhaps you should try some spelling variations:
cua viet » ca viet, hoa viet, cua vat
manh hai » lanh hai, minh hai, thanh hai
hieu luc » hieu luat, hieu qua
luc cham » luc tham, tuc cham, phuc cham
dang xay » dang van, van xay
xay hoi » xa hoi, tay hoi, cay phoi
ky dang » ky nang, ky danh
te sach » toc sach
hai cua » thai cua, dai cua, hoi cua
tu sach » thu sach, su sach, tu cach
xuc va » duc va, luc va, xac va
tuc va » thuc va, truc va, tuc xa

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((tu sach) or (te sach)) ky dang xay hoi. hieu luc cham ((xuc va) or (tuc va)) manh hai cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (te sach)) ky dang xay hoi. hieu luc cham ((xuc va) OR (tuc va)) manh hai cua viet.
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (te sach)) ky dang xay hoi. hieu luc cham ((xuc va) or (tuc va)) manh hai cua viet*.