Perhaps you should try some spelling variations:
thanh di » thanh doi, thanh de, thanh do
hieu van » hieu va, thien van, lieu va
su sach » so sach, vu sach
truc va » thuc va, thuc vat, trung va
cua tre » cua te, cuu tre, cua triet
van cau » van dau, van hau, van chat
dang ha » dong ha, dung ha, lang ha
xac va » ac va, bac va, mac va
y dang » ky dang, 2 dang, _ dang
tac va » tac da, tac xa, tuc va
ha hoi » hoa hoi, ha noi, xa hoi
di cua » dai cua, doi cua, de cua

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 y dang ha hoi. hieu van cau ((((xac va) or (tac va))) or (truc va)) thanh di cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach y dang ha hoi. hieu van cau ((((xac va) OR (tac va))) OR (truc va)) thanh di cua tre.
• Adding a wildcard symbol may retrieve word variants: su sach y dang ha hoi. hieu van cau ((((xac va) or (tac va))) or (truc va)) thanh di cua tre*.