Perhaps you should try some spelling variations:
cac nuoc » cap nuoc, hoc nuoc, dat nuoc
sach ky » sach y, sach ty, sach kem
nang xa » nang x, lang xa, nang ma
qua cac » cua cac
va danh » va dinh, va dan, va hanh
danh de » hanh de, dan de, dang de
cua tre » cua te, cua triet, dua tren
cuu tre » cau tren, cau treo
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)) nang xa hoi. hieu qua cac nuoc va danh de ((cua tre) OR (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ky) OR (sac ky)) nang xa hoi. hieu qua cac nuoc va danh de ((cua tre) OR (cuu tre)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach ky) or (sac ky)) nang xa hoi. hieu qua cac nuoc va danh de ((cua tre) OR (cuu tre))".
• Adding a wildcard symbol may retrieve word variants: tu ((sach ky) or (sac ky)) nang xa hoi. hieu qua cac nuoc va danh de ((cua tre) OR (cuu tre))*.