Perhaps you should try some spelling variations:
vu sach » vu bach, su sach, vu khach
sach le » cach le, sach de, sach lo
le dang » le tang, le dan, le quang
dang xa » dang xay, lang xa, dang ha
hieu va » lieu va, hieu qua
va giao » van giao, va giai, va gia
va hanh » van hanh, va thanh, va danh
vai va » dai va, hai va, lai va
thiet » thieu

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 le dang xa hoi. hieu va giao duc va hanh ((vai va) OR (mai va)) thiet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu sach le dang xa hoi. hieu va giao duc va hanh ((vai va) OR (mai va)) thiet".
• Adding a wildcard symbol may retrieve word variants: vu sach le dang xa hoi. hieu va giao duc va hanh ((vai va) OR (mai va)) thiet*.