Perhaps you should try some spelling variations:
sach nuoc » sach duoc, cac nuoc, bach tuoc
hieu viec » nhieu viec, hieu ve, sieu viet
hieu van » hieu va, thien van, lieu va
doi cua » dai cua, hoi cua
dan doi » dan hoi, dan toi, van doi
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
va dan » ca dan, va dao, va dau

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 van)) sach nuoc va dan 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 van)) sach nuoc va dan doi cua tre.
• Adding a wildcard symbol may retrieve word variants: su ((sach ky) or (sac ky)) nang xa hoi. ((hieu viec) or (hieu van)) sach nuoc va dan doi cua tre*.