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
so sach » so sanh, bo sach, co sach
sach ky » sac ky, sach y, sach ty
hieu ve » hieu va, hieu van
va danh » va dinh, va dan, va hanh
doi cua » dai cua, hoi cua
cua tre » cua te, cuu tre, cua triet
nang o » nang co, nang ho, nang ro
o hoi » co hoi, o hoc, o hai

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: so sach ky nang o 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: so sach ky nang o hoi. ((hieu viec) OR (hieu ve)) sach nuoc va danh doi cua tre.
• Adding a wildcard symbol may retrieve word variants: so sach ky nang o hoi. ((hieu viec) or (hieu ve)) sach nuoc va danh doi cua tre*.