Perhaps you should try some spelling variations:
thuoc cao » thuoc co, thuc cao, thuoc bao
doc sach » hoc sach, toc sach, nuoc sach
sach kho » bach khoa, sach dao, sach nha
kho tang » cao tang
hieu van » hieu va, thien van, lieu va
cau treo » cau theo, cau tren, cau triet
tang xa » trang xa, tang ma, lang xa
thuc ca » thuc cua, thuc can, thuc cao
dan va » doan va, dan ca, ban va
va cau » van cau, va cac, va dau

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

• Performing a fuzzy search may retrieve terms with similar spellings: doc sach kho tang xa hoi. hieu van nam ((thuc ca) or (thuoc cao)) dan va cau treo~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc sach kho tang xa hoi. hieu van nam ((thuc ca) OR (thuoc cao)) dan va cau treo.
• Adding a wildcard symbol may retrieve word variants: doc sach kho tang xa hoi. hieu van nam ((thuc ca) or (thuoc cao)) dan va cau treo*.