Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
danh dai » danh di, danh sai, vanh dai
danh dau » lanh dao, hang dau, danh tu
nang xa » nang x, lang xa, nang ma
hieu va » lieu va, hieu qua
cua tre » cua te, cuu tre, cua triet
te cac » tu cac, ve cac, te cao
va am » va lam, va cam
thuc » thu

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((toc sach) or (te cac)) ky nang xa hoi. hieu va am thuc vat ((danh dai) or (danh dau)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((toc sach) OR (te cac)) ky nang xa hoi. hieu va am thuc vat ((danh dai) OR (danh dau)) cua tre.
• Adding a wildcard symbol may retrieve word variants: ((toc sach) or (te cac)) ky nang xa hoi. hieu va am thuc vat ((danh dai) or (danh dau)) cua tre*.