Perhaps you should try some spelling variations:
chat thuc » thuat thuc, nhan thuc, chat thai
hieu quan » lieu quan, thien quan, lien quan
thu sach » tu sach, thuat sach, thuoc sach
thuc day » thuc dan, thuc vat
day danh » day manh, dai danh, dao danh
danh dau » lanh dao, hang dau, danh tu
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
dau cua » dai cua, day cua, cau cua
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: thu sach ky nang xa hoi. ((hieu quan) or (hieu qua)) chat thuc day danh dau cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ky nang xa hoi. ((hieu quan) OR (hieu qua)) chat thuc day danh dau cua tre.
• Adding a wildcard symbol may retrieve word variants: thu sach ky nang xa hoi. ((hieu quan) or (hieu qua)) chat thuc day danh dau cua tre*.