Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
su sach » so sach, vu sach
hieu ve » hieu va
va hanh » van hanh, va thanh, va danh
vai cua » hai cua, lai cua, bai cua
y nang » ky nang, ly nang, v nang
cac tu » cac thu, cach tu, cac du
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 y nang x hoi. ((hieu ve) or (hieu van)) cac tu va hanh ((vai cua) OR (dai cua)) viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach y nang x hoi. ((hieu ve) OR (hieu van)) cac tu va hanh ((vai cua) OR (dai cua)) viet*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach y nang x hoi. ((hieu ve) or (hieu van)) cac tu va hanh ((vai cua) OR (dai cua)) viet*".