Perhaps you should try some spelling variations:
sach nuoc » sach duoc, cac nuoc, bach tuoc
hieu viec » nhieu viec, sieu viet, hieu hien
dinh doi » dinh moi, tinh doi, dinh toi
hieu ve » hieu va, hieu van
doi cua » dai cua, hoi cua
va dinh » van dinh, va kinh, va tinh
cua tre » cua te, cuu tre, cua triet
sach ty » sach tu, sach thu, xach tay
nang xa » nang x, lang xa, nang ma

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 ty) OR (sach y)) nang xa hoi. ((hieu viec) or (hieu ve)) sach nuoc va dinh doi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach ty) OR (sach y)) nang xa hoi. ((hieu viec) OR (hieu ve)) sach nuoc va dinh doi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su ((sach ty) OR (sach y)) nang xa hoi. ((hieu viec) or (hieu ve)) sach nuoc va dinh doi cua tre".
• Adding a wildcard symbol may retrieve word variants: su ((sach ty) OR (sach y)) nang xa hoi. ((hieu viec) or (hieu ve)) sach nuoc va dinh doi cua tre*.