Perhaps you should try some spelling variations:
van dung » van dong, xay dung, tin dung
vu sach » vu bach, su sach, vu khach
sach ky » sac ky, sach y, sach ty
nang ma » tang ma, sang ma, nang cao
hieu ve » hieu va, hieu van
va dung » va duong, vat dung, va ung
tai cua » thai cua, tai cuc, tri cua
cua tre » cua te, cuu tre, cua triet
ma hoi » mai hoi, xa hoi, ma hoa
nam tu » nam thu, nam thuc

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 nang ma hoi. ((hieu ve) or (lieu va)) nam tu ((va dung) OR (van dung)) tai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach ky nang ma hoi. ((hieu ve) OR (lieu va)) nam tu ((va dung) OR (van dung)) tai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu sach ky nang ma hoi. ((hieu ve) or (lieu va)) nam tu ((va dung) OR (van dung)) tai cua tre".
• Adding a wildcard symbol may retrieve word variants: vu sach ky nang ma hoi. ((hieu ve) or (lieu va)) nam tu ((va dung) OR (van dung)) tai cua tre*.