Perhaps you should try some spelling variations:
nham thuc » nhan thuc, nam thuc, nham thu
sach ky » sach y, sach ty, sach kem
va danh » va dinh, va dan, va hanh
va vanh » va van, va hanh, va anh
va nham » va cham, va tham, va nha
hieu va » lieu va, hieu qua
dang xa » dang xay, lang xa, dang ha
cua tre » cua te, cuu tre, cua triet
sac ky » cac ky, sai ky

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) or (sac ky)) dang xa hoi. hieu va nham thuc ((va vanh) OR (va danh)) dai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ky) OR (sac ky)) dang xa hoi. hieu va nham thuc ((va vanh) OR (va danh)) dai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach ky) or (sac ky)) dang xa hoi. hieu va nham thuc ((va vanh) OR (va danh)) dai cua tre".
• Adding a wildcard symbol may retrieve word variants: tu ((sach ky) or (sac ky)) dang xa hoi. hieu va nham thuc ((va vanh) OR (va danh)) dai cua tre*.