Perhaps you should try some spelling variations:
sach tham » sach nha
chua tre » chua tri, cua tre, chua trieu
lam duoc » nam duoc, luat duoc, lam thuoc
nang cai » nang cao, nang tai, nang cap
hieu van » hieu va, thien van, lieu va
sach thu » sach thue, sach thieu, cach thuc
nang ca » nang cao, nang cap, nang can
duoc va » nuoc va, duc va, duoc ma
lang ha » long ha
van lam » van nam
ha hoi » hoa hoi, ha noi, xa hoi

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

• Performing a fuzzy search may retrieve terms with similar spellings: te ((sach thu) or (sach tham)) lang ha hoi. hieu van lam duoc va ((nang ca) or (nang cai)) chua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te ((sach thu) OR (sach tham)) lang ha hoi. hieu van lam duoc va ((nang ca) OR (nang cai)) chua tre.
• Adding a wildcard symbol may retrieve word variants: te ((sach thu) or (sach tham)) lang ha hoi. hieu van lam duoc va ((nang ca) or (nang cai)) chua tre*.