Perhaps you should try some spelling variations:
sach ty » sach y, sach tu, sach thu
het cua » det cua, hat cua, nhiet cua
va hanh » van hanh, va thanh, ban hanh
va danh » va dinh, va dan, dia danh
cao duc » dao duc, cao suc, giao duc
cua tre » cua te, cuu tre, cua triet
hieu va » lieu va, hieu qua
nang xa » nang x, lang xa, nang ma
cach tu » cach thuc
va cao » va cac, va co, va dao

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

• Performing a fuzzy search may retrieve terms with similar spellings: te ((sach ty) or (cach tu)) nang xa hoi. hieu va cao duc ((va danh) OR (va hanh)) het cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te ((sach ty) OR (cach tu)) nang xa hoi. hieu va cao duc ((va danh) OR (va hanh)) het cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te ((sach ty) or (cach tu)) nang xa hoi. hieu va cao duc ((va danh) OR (va hanh)) het cua tre".
• Adding a wildcard symbol may retrieve word variants: te ((sach ty) or (cach tu)) nang xa hoi. hieu va cao duc ((va danh) OR (va hanh)) het cua tre*.