Perhaps you should try some spelling variations:
vien cac » vien bach, vien da, gian cac
vien dai » hien dai
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
dan tai » van tai, dan thi, han tai
tai cua » thai cua, tai cuc, tri cua
cua tre » cua te, cuu tre, cua triet
va dan » ca dan, va dao, va dau
bo va » bao va, do va, so va

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 cac) or (vien dai)) bo va dan tai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang xa hoi. hieu ((vien cac) OR (vien dai)) bo va dan tai cua tre.
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang xa hoi. hieu ((vien cac) or (vien dai)) bo va dan tai cua tre*.