Perhaps you should try some spelling variations:
te sach » toc sach
va hanh » van hanh, va thanh, ban hanh
va danh » va dinh, va dan, dia danh
cac duc » cac du, cao duc, cac dac
hieu va » lieu va, hieu qua
nang ma » tang ma, sang ma, nang cao
lang xa » lang ha, dang xay, lang van
ca cua » co cua
cua te » cua tu

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

• If you are trying to use Boolean operators, they must be ALL CAPS: te sach y ((lang xa) OR (nang ma)) hoi. hieu va cac duc ((va danh) OR (va hanh)) ca cua te~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach y ((lang xa) or (nang ma)) hoi. hieu va cac duc ((va danh) OR (va hanh)) ca cua te~".
• Adding a wildcard symbol may retrieve word variants: te sach y ((lang xa) or (nang ma)) hoi. hieu va cac duc ((va danh) OR (va hanh)) ca cua te*.