Perhaps you should try some spelling variations:
hanh vai » hanh vi, hanh va, hanh tai
hieu van » thien van, lieu va, hieu ve
tu sach » thu sach, su sach, te sach
cam tuc » cam xuc, cam tu, nam thuc
cuu tre » cau tren, cau treo
xa hanh » xa thanh, xa khanh, va hanh
hieu va » lieu va, hieu qua
sach ky » sac ky, sach y, sach ty
tang ma » mang may, tang van
ky tang » ky nang, ky dang, kho tang
cua tre » cua te, cua triet, dua tren
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: tu sach ky tang ma hoi. ((hieu van) OR (hieu va)) cam tuc xa hanh vai ((cuu tre) or (cua tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky tang ma hoi. ((hieu van) OR (hieu va)) cam tuc xa hanh vai ((cuu tre) OR (cua tre)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky tang ma hoi. ((hieu van) OR (hieu va)) cam tuc xa hanh vai ((cuu tre) or (cua tre))".
• Adding a wildcard symbol may retrieve word variants: tu sach ky tang ma hoi. ((hieu van) OR (hieu va)) cam tuc xa hanh vai ((cuu tre) or (cua tre))*.