Perhaps you should try some spelling variations:
cau tren » cu tren, dau tren, ca tren
hieu va » lieu va, hieu qua
cao duc » dao duc, cao suc, giao duc
va hanh » van hanh, va thanh, va danh
hanh tu » anh tu, danh tu
sach v » sach va, sach 2, sach vay
va cao » va cac, va co, va dao
tu cau » tu cac, cu cau, tu can
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: toc ((sach v) or (sach y)) nang x hoi. hieu va cao duc va hanh tu cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc ((sach v) OR (sach y)) nang x hoi. hieu va cao duc va hanh tu cau tren.
• Adding a wildcard symbol may retrieve word variants: toc ((sach v) or (sach y)) nang x hoi. hieu va cao duc va hanh tu cau tren*.