Perhaps you should try some spelling variations:
thien van » thi van
hieu van » hieu va, lieu va, hieu ve
van dinh » van minh, van dich, va dinh
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
va tinh » may tinh
cua tre » cua te, cuu tre, cua triet
va cua » va chua, via cua, ca cua

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)) chao xu ((va tinh) or (van dinh)) va 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)) chao xu ((va tinh) OR (van dinh)) va cua tre.
• Adding a wildcard symbol may retrieve word variants: su sach ky nang xa hoi. ((hieu van) or (thien van)) chao xu ((va tinh) or (van dinh)) va cua tre*.