Perhaps you should try some spelling variations:
cua viet » ca viet, hoa viet, cua vat
dang xay » dang van, van xay
thanh va » thanh van, hanh va, thanh ha
trung va » truong va, trang va, trung ha
cua tre » cua te, cuu tre, cua triet
vu sach » vu bach, su sach, vu khach
sach ky » sac ky, sach y, sach ty
truc va » thuc va, thuc vat
hieu ve » hieu va, hieu van
xay hoi » xa hoi, tay hoi, cay phoi
ky dang » ky nang, ky danh
ve cau » ke cau, va cau, ve cac

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

• Performing a fuzzy search may retrieve terms with similar spellings: vu sach ky dang xay hoi. hieu ve cau ((truc va) OR (trung va)) thanh va ((cua tre) or (cua viet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach ky dang xay hoi. hieu ve cau ((truc va) OR (trung va)) thanh va ((cua tre) OR (cua viet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu sach ky dang xay hoi. hieu ve cau ((truc va) OR (trung va)) thanh va ((cua tre) or (cua viet))".
• Adding a wildcard symbol may retrieve word variants: vu sach ky dang xay hoi. hieu ve cau ((truc va) OR (trung va)) thanh va ((cua tre) or (cua viet))*.