Perhaps you should try some spelling variations:
dung tren » dung trong, dung trung
tinh lai » tinh lao, tinh hai, minh lai
te sach » toc sach
va tinh » may tinh
hieu va » lieu va, hieu qua
sach ty » sach y, sach tu, sach thu
hieu ve » hieu van
nang ma » tang ma, sang ma, nang cao
ty nang » ky nang, ty xang, ty hang
cuu tre » cua tre, cau tren, cau treo

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 ty nang ma hoa. ((hieu ve) or (hieu va)) pham duc va tinh lai ((dung tren) or (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ty nang ma hoa. ((hieu ve) OR (hieu va)) pham duc va tinh lai ((dung tren) OR (cuu tre)).
• Adding a wildcard symbol may retrieve word variants: te sach ty nang ma hoa. ((hieu ve) or (hieu va)) pham duc va tinh lai ((dung tren) or (cuu tre))*.