Perhaps you should try some spelling variations:
thong hai » thong thai, thong ha, thong tai
sach thu » sach thue, sach thieu, sach tham
hieu van » hieu va, thien van, lieu va
hang hai » hoang hai, hang tai, thanh hai
van cao » van dao, van bao, van hao
cao suc » cao su, cao duc
sach ty » sach y, sach tu, xach tay
cua tre » cua te, cuu tre, cua triet
suc va » duc va, tuc va, luc va
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 ty) or (sach thu)) nang x hoi. hieu van cao suc va ((hang hai) or (thong hai)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach ty) OR (sach thu)) nang x hoi. hieu van cao suc va ((hang hai) OR (thong hai)) cua tre.
• Adding a wildcard symbol may retrieve word variants: su ((sach ty) or (sach thu)) nang x hoi. hieu van cao suc va ((hang hai) or (thong hai)) cua tre*.