Perhaps you should try some spelling variations:
bac trung » ba trung, dac trung, bao trung
hieu van » hieu va, thien van, lieu va
trung va » truong va, trang va, trung ha
su sach » so sach, vu sach
danh vi » dinh vi, danh di, danh va
van bac » van ban, van bao, van hac
nang xa » nang x, lang xa, nang ma
so sanh » do sanh
cuu tre » cua tre, cau tren, cau treo

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 sanh)) ky nang xa hoi. hieu van bac trung va ((danh vi) OR (hanh vi)) cuu tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sach) or (so sanh)) ky nang xa hoi. hieu van bac trung va ((danh vi) OR (hanh vi)) cuu tre~".
• Adding a wildcard symbol may retrieve word variants: ((su sach) or (so sanh)) ky nang xa hoi. hieu van bac trung va ((danh vi) OR (hanh vi)) cuu tre*.