Perhaps you should try some spelling variations:
dat khanh » van khanh, duy khanh
toc sach » hoc sach, doc sach, thuoc sach
da thanh » dao thanh, dat thanh, dam thanh
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
hieu va » lieu va, hieu qua
doi cua » dai cua, hoi cua
cua tre » cua te, cuu tre, cua triet
va am » va lam, va cam

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 ky nang xa hoi. hieu va am thuc ((da thanh) or (dat khanh)) doi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ky nang xa hoi. hieu va am thuc ((da thanh) OR (dat khanh)) doi cua tre.
• Adding a wildcard symbol may retrieve word variants: toc sach ky nang xa hoi. hieu va am thuc ((da thanh) or (dat khanh)) doi cua tre*.