Perhaps you should try some spelling variations:
trung van » truong van, trong van, trung va
han lang » nhan lang, ban lang, ha lang
van hanh » van thanh, ban hanh, van anh
su sach » vu sach
so sach » so sanh, bo sach, co sach
lang xa » lang ha, dang xay, lang van
hieu va » hieu qua
su tien » su kien, su hien, tu tieng
vi su » va su, ve su, ki su

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: ((su sach) OR (so sach)) han lang xa hoi. ((hieu va) OR (lieu va)) tai trung van hanh vi su tien~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sach) OR (so sach)) han lang xa hoi. ((hieu va) or (lieu va)) tai trung van hanh vi su tien~".
• Adding a wildcard symbol may retrieve word variants: ((su sach) OR (so sach)) han lang xa hoi. ((hieu va) or (lieu va)) tai trung van hanh vi su tien*.