Perhaps you should try some spelling variations:
thien van » thi van
lam trung » lam truong, nam trung, lam trong
trung va » truong va, trang va, trung ha
trinh vi » trinh va, trinh ve, trinh viet
hieu van » hieu va, lieu va, hieu ve
tinh vi » tinh voi, tinh va, dinh vi
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
cua tre » cua te, cuu tre, cua triet

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 ky nang xa hoi. ((hieu van) or (thien van)) lam trung va ((tinh vi) OR (trinh vi)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky nang xa hoi. ((hieu van) OR (thien van)) lam trung va ((tinh vi) OR (trinh vi)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky nang xa hoi. ((hieu van) or (thien van)) lam trung va ((tinh vi) OR (trinh vi)) cua tre".
• Adding a wildcard symbol may retrieve word variants: su sach ky nang xa hoi. ((hieu van) or (thien van)) lam trung va ((tinh vi) OR (trinh vi)) cua tre*.