Perhaps you should try some spelling variations:
hanh kien » danh kien, anh kien, thanh vien
vu sach » vu bach, su sach, vu khach
kien su » nien su, tien su, vien sau
vuc van » duc van, luc van, thuc van
xuc van » duc van, luc van, xuc ban
hieu va » lieu va, hieu qua
sach vu » sach va, sach tu, sach uu
sang ma » tang ma, nang ma, sang tao
su viet » so viet

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

• Performing a fuzzy search may retrieve terms with similar spellings: vu sach vu ((nang cao) or (sang ma)) hoi. hieu va cac ((xuc van) OR (vuc van)) hanh kien su viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach vu ((nang cao) OR (sang ma)) hoi. hieu va cac ((xuc van) OR (vuc van)) hanh kien su viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu sach vu ((nang cao) or (sang ma)) hoi. hieu va cac ((xuc van) OR (vuc van)) hanh kien su viet".
• Adding a wildcard symbol may retrieve word variants: vu sach vu ((nang cao) or (sang ma)) hoi. hieu va cac ((xuc van) OR (vuc van)) hanh kien su viet*.