Perhaps you should try some spelling variations:
thanh di » thanh doi, thanh do, thanh dinh
thanh de » hanh de, thanh ve, thanh do
su sach » so sach, vu sach
sach ty » sach y, sach tu, sach thu
ty hang » ly hang, ty xang, thi hang
hang xa » hoang xa, hang va, hang ca
duc ban » duc tan, duc van, dua ban
cua tre » cua te, cuu tre, cua triet

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