Perhaps you should try some spelling variations:
thien van » thi van
hieu van » hieu va, lieu va, hieu ve
van hanh » van thanh, ban hanh, van anh
su sach » so sach, vu sach
nang xa » nang x, lang xa, nang ma
vai cua » dai cua, lai cua, bai cua
hai cua » thai cua, dai cua, hoi cua
y nang » ky nang, ly nang, v nang
cam tu » cam thu, nam tu, dam tu
tu van » tu va

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 xa hoi. ((hieu van) OR (thien van)) cam tu van hanh ((vai cua) or (hai cua)) viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach y nang xa hoi. ((hieu van) OR (thien van)) cam tu van hanh ((vai cua) OR (hai cua)) viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach y nang xa hoi. ((hieu van) OR (thien van)) cam tu van hanh ((vai cua) or (hai cua)) viet".
• Adding a wildcard symbol may retrieve word variants: su sach y nang xa hoi. ((hieu van) OR (thien van)) cam tu van hanh ((vai cua) or (hai cua)) viet*.