Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van ban
te sach » toc sach
sach vu » sach va, sach tu, sach uu
vu dang » su dang, vu quang, cua dang
dang xa » dang xay, lang xa, dang ha
hieu va » lieu va
van anh » van thanh, tuan anh, van minh
vai cua » dai cua, hai cua, lai cua
cua su » qua su

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 vu dang xa hoi. ((hieu va) or (hieu qua)) cau truc ((van hanh) OR (van anh)) vai cua su~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach vu dang xa hoi. ((hieu va) OR (hieu qua)) cau truc ((van hanh) OR (van anh)) vai cua su.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach vu dang xa hoi. ((hieu va) or (hieu qua)) cau truc ((van hanh) OR (van anh)) vai cua su".
• Adding a wildcard symbol may retrieve word variants: te sach vu dang xa hoi. ((hieu va) or (hieu qua)) cau truc ((van hanh) OR (van anh)) vai cua su*.