Perhaps you should try some spelling variations:
thanh duoc » hanh duoc, tranh duoc, thanh phuoc
van thanh » ban thanh, van tuan
thanh va » thanh van, hanh va, thanh ha
thanh ve » hanh ve, thanh vien, thanh van
hieu van » hieu va, thien van, lieu va
sach thu » sach thue, sach thieu, sach tham
duoc va » nuoc va, duc va, duoc ma
sach ty » sach y, sach tu, xach tay
cau tre » cau tren, cau treo, cau tra
x hoi » xa hoi, o hoi, x ho

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 thu) or (sach ty)) nang x hoi. hieu van thanh duoc va ((thanh ve) OR (thanh va)) cau tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach thu) OR (sach ty)) nang x hoi. hieu van thanh duoc va ((thanh ve) OR (thanh va)) cau tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su ((sach thu) or (sach ty)) nang x hoi. hieu van thanh duoc va ((thanh ve) OR (thanh va)) cau tre".
• Adding a wildcard symbol may retrieve word variants: su ((sach thu) or (sach ty)) nang x hoi. hieu van thanh duoc va ((thanh ve) OR (thanh va)) cau tre*.