Perhaps you should try some spelling variations:
dung tren » dung trong, dung trung
thanh lai » thanh hai, thanh lap, thanh loi
va thanh » gia thanh, ban thanh, va tinh
te sach » toc sach
hieu va » lieu va, hieu qua
sach ky » sac ky, sach y, sach ty
hieu ve » hieu van
nang ma » tang ma, sang ma, nang cao
cuu tre » cua tre, cau tren, cau treo
ma hoi » mai hoi, xa hoi, ma hoa

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sach ky nang ma hoi. ((hieu ve) or (hieu va)) pham duc va thanh lai ((dung tren) or (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ky nang ma hoi. ((hieu ve) OR (hieu va)) pham duc va thanh lai ((dung tren) OR (cuu tre)).
• Adding a wildcard symbol may retrieve word variants: te sach ky nang ma hoi. ((hieu ve) or (hieu va)) pham duc va thanh lai ((dung tren) or (cuu tre))*.