Perhaps you should try some spelling variations:
cua triet » cua viet, su triet
hieu van » hieu va, thien van, lieu va
va triet » va thiet, va trien, ve triet
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
nang ma » tang ma, sang ma, nang cao
nam tuc » nam thuc, nam truc, nam tu
xa hanh » xa thanh, xa khanh, va hanh
cua tre » cua te, cuu tre, 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 nang ma hoi. hieu van nam tuc xa hanh vi ((cua tre) or (((cua triet) OR (va triet))))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang ma hoi. hieu van nam tuc xa hanh vi ((cua tre) OR (((cua triet) OR (va triet))))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang ma hoi. hieu van nam tuc xa hanh vi ((cua tre) or (((cua triet) OR (va triet))))*".