Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, thieu nien
tu sach » thu sach, su sach, te sach
va kinh » va tinh, qua kinh
vai cua » dai cua, hai cua, lai cua
va hanh » van hanh, va thanh, va danh
cua tre » cua te, cuu tre, cua triet
nang xa » nang x, lang xa, nang ma
sach ky » sac ky, sach y, sach ty
dai o » dao o, dai 2, di o

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ky nang xa hoi. hieu vien ((dai so) or (dai o)) ((va kinh) or (va hanh)) vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang xa hoi. hieu vien ((dai so) OR (dai o)) ((va kinh) OR (va hanh)) vai cua tre.
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang xa hoi. hieu vien ((dai so) or (dai o)) ((va kinh) or (va hanh)) vai cua tre*.