Perhaps you should try some spelling variations:
van thanh » ban thanh, van tuan
hanh lai » hanh lam, hanh tai, thanh lap
hieu van » hieu va, thien van, lieu va
lai cua » dai cua, hai cua, lai chau
tu sach » thu sach, su sach, te sach
nang ma » tang ma, sang ma, mang may
cua tre » cua te, cuu tre, cua triet
sach v » sach va, sach y, sach 2
loc va » luc va

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach v ((nang ma) or (nang cao)) hoi. hieu van thanh ((loc va) OR (hoc va)) hanh lai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach v ((nang ma) OR (nang cao)) hoi. hieu van thanh ((loc va) OR (hoc va)) hanh lai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach v ((nang ma) or (nang cao)) hoi. hieu van thanh ((loc va) OR (hoc va)) hanh lai cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sach v ((nang ma) or (nang cao)) hoi. hieu van thanh ((loc va) OR (hoc va)) hanh lai cua tre*.