Perhaps you should try some spelling variations:
thanh van » thanh san, thanh toan, thanh phan
ban thanh » ban hanh, ban hang
nam duoc » nam thuoc, da duoc, dat duoc
hieu van » hieu va, thien van, lieu va
su sach » so sach, vu sach
van cuu » van cau, van chu, van cu
lam duc » lam duoc, pham duc, lam dung
sach ky » sac ky, sach y, sach ty
nang ma » tang ma, sang ma, nang cao
cuu tre » cua tre, cau tren, cau treo

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 x) or (nang ma)) hoi. hieu van ((lam duc) OR (nam duoc)) ban thanh van cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky ((nang x) OR (nang ma)) hoi. hieu van ((lam duc) OR (nam duoc)) ban thanh van cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky ((nang x) or (nang ma)) hoi. hieu van ((lam duc) OR (nam duoc)) ban thanh van cuu tre".
• Adding a wildcard symbol may retrieve word variants: su sach ky ((nang x) or (nang ma)) hoi. hieu van ((lam duc) OR (nam duoc)) ban thanh van cuu tre*.