Perhaps you should try some spelling variations:
nam duoc » nam thuoc, da duoc, dat duoc
hieu van » hieu va, thien van, lieu va
hanh van » thanh van, khanh van, hanh va
ban hanh » ban hang
cua tre » cua te, cua triet, dua tren
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
lang xa » lang ha, dang xay, lang van
ky lang » ky nang, ky dang, ky tang
cuu 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 lang xa hoi. hieu van ((pham duc) or (nam duoc)) ban hanh van ((cua tre) OR (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky lang xa hoi. hieu van ((pham duc) OR (nam duoc)) ban hanh van ((cua tre) OR (cuu tre)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky lang xa hoi. hieu van ((pham duc) or (nam duoc)) ban hanh van ((cua tre) OR (cuu tre))".
• Adding a wildcard symbol may retrieve word variants: su sach ky lang xa hoi. hieu van ((pham duc) or (nam duoc)) ban hanh van ((cua tre) OR (cuu tre))*.