Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
sach da » sach dao, sach dat, sach dau
hoi cua » hoi chuc
vai cua » dai cua, hai cua, lai cua
su sach » so sach, vu sach
hieu ve » hieu van
da nang » cam nang, kha nang, cao nang
hieu va » lieu va, hieu qua
cac tu » cac thu, cach tu, cac du
tu van » tu va
x hoi » xa hoi, o hoi, x ho

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

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