Perhaps you should try some spelling variations:
thanh dai » thanh hai, thanh tai, thanh dat
cua triet » cua viet, su triet, va triet
hieu van » hieu va, thien van, lieu va
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
nang ma » tang ma, sang ma, nang cao
van lam » van nam
dua ban » dia ban, cua ban, mua ban
qua ban » cua ban, qua quan
cua tre » cua te, cuu tre, dua tren

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 hoa. hieu van lam ((dua ban) or (qua ban)) thanh dai ((cua tre) OR (cua triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang ma hoa. hieu van lam ((dua ban) OR (qua ban)) thanh dai ((cua tre) OR (cua triet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang ma hoa. hieu van lam ((dua ban) or (qua ban)) thanh dai ((cua tre) OR (cua triet))".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang ma hoa. hieu van lam ((dua ban) or (qua ban)) thanh dai ((cua tre) OR (cua triet))*.