Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
hieu van » hieu va, thien van, lieu va
lam duc » lam duoc, pham duc, nam duoc
dan cua » dan ca, ban cua, dai cua
van cua » vang cua, ban cua, nan cua
duc ban » duc tan, duc van, dua ban
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
nang ma » tang ma, sang ma, nang cao
nang xa » nang x, lang xa, mang xa
van lam » van nam

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: su sach ky ((nang xa) OR (nang ma)) hoi. hieu van lam duc ban thanh ((van cua) or (dan cua)) triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky ((nang xa) OR (nang ma)) hoi. hieu van lam duc ban thanh ((van cua) OR (dan cua)) triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky ((nang xa) OR (nang ma)) hoi. hieu van lam duc ban thanh ((van cua) or (dan cua)) triet".
• Adding a wildcard symbol may retrieve word variants: su sach ky ((nang xa) OR (nang ma)) hoi. hieu van lam duc ban thanh ((van cua) or (dan cua)) triet*.