Perhaps you should try some spelling variations:
sach nuoc » sach duoc, cac nuoc, bach tuoc
hieu viec » nhieu viec, sieu viet, hieu hien
danh doi » danh di, thanh doi, dung doi
hieu ve » hieu va, hieu van
doi cua » dai cua, hoi cua
va danh » va dinh, va dan, va hanh
cua tre » cua te, cuu tre, cua triet
sach ky » sach y, sach ty, sach kem
nang xa » nang x, lang xa, nang ma
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: su ((sach ky) OR (sac ky)) nang xa hoi. ((hieu viec) or (hieu ve)) sach nuoc va danh doi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach ky) OR (sac ky)) nang xa hoi. ((hieu viec) OR (hieu ve)) sach nuoc va danh doi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su ((sach ky) OR (sac ky)) nang xa hoi. ((hieu viec) or (hieu ve)) sach nuoc va danh doi cua tre".
• Adding a wildcard symbol may retrieve word variants: su ((sach ky) OR (sac ky)) nang xa hoi. ((hieu viec) or (hieu ve)) sach nuoc va danh doi cua tre*.