Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
hieu van » hieu va, thien van, lieu va
thuc cao » thuoc cao, thuc co, thuc can
cau treo » cau theo, cau tren, cau triet
sach ky » sac ky, sach y, sach ty
ky tang » ky nang, ky dang, kho tang
tang xa » trang xa, tang ma, lang xa
thuc ca » thuc cua, thuc can, thuc va
dan va » doan va, dan ca, han va

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

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