Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
hieu viec » nhieu viec, hieu ve, sieu viet
hieu vien » hieu hien, thieu nien, hieu tieng
da thanh » dao thanh, dat thanh, dam thanh
sach ky » sac ky, sach y, sach ty
cac tac » cac toc, cac bac, cac dac
x hoi » xa hoi, o hoi, x ho
ve va » ve van, te va, le va
ke va » te va

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

• Performing a fuzzy search may retrieve terms with similar spellings: thuoc sach ky nang x hoi. ((hieu vien) OR (hieu viec)) cac tac da thanh ((ve va) or (ke va)) triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuoc sach ky nang x hoi. ((hieu vien) OR (hieu viec)) cac tac da thanh ((ve va) OR (ke va)) triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuoc sach ky nang x hoi. ((hieu vien) OR (hieu viec)) cac tac da thanh ((ve va) or (ke va)) triet".
• Adding a wildcard symbol may retrieve word variants: thuoc sach ky nang x hoi. ((hieu vien) OR (hieu viec)) cac tac da thanh ((ve va) or (ke va)) triet*.