Perhaps you should try some spelling variations:
thien van » thi van
nam truoc » nam thuoc, lam truoc, nam truc
truoc xa » truoc xay, truoc bua, truoc dam
va triet » va thiet, va trien, ve triet
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
hieu va » lieu va, hieu qua
xa hanh » xa thanh, xa khanh, va hanh
vi va » vi van, vai va, vu va

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 doc) OR (nang luc)) hai. ((thien van) or (hieu va)) nam truoc xa hanh vi va triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky ((nang doc) OR (nang luc)) hai. ((thien van) OR (hieu va)) nam truoc xa hanh vi va triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky ((nang doc) OR (nang luc)) hai. ((thien van) or (hieu va)) nam truoc xa hanh vi va triet".
• Adding a wildcard symbol may retrieve word variants: tu sach ky ((nang doc) OR (nang luc)) hai. ((thien van) or (hieu va)) nam truoc xa hanh vi va triet*.