Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
thanh vi » hanh vi, thanh va, thanh ve
cham duc » pham duc, pham duy, phan duc
vu sach » vu bach, su sach, vu khach
cao hoi » cau hoi, co hoi, cao hoc
ty nang » ky nang, ty xang, ty hang
so sach » so sanh, bo sach, co sach
vi cua » vai cua, di cua
cua tu » cua tuc, cua su, cua cu

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((vu sach) or (so sach)) ty nang cao hoi. hieu qua ((cham duc) OR (cham soc)) ban thanh vi cua tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((vu sach) OR (so sach)) ty nang cao hoi. hieu qua ((cham duc) OR (cham soc)) ban thanh vi cua tu.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((vu sach) or (so sach)) ty nang cao hoi. hieu qua ((cham duc) OR (cham soc)) ban thanh vi cua tu".
• Adding a wildcard symbol may retrieve word variants: ((vu sach) or (so sach)) ty nang cao hoi. hieu qua ((cham duc) OR (cham soc)) ban thanh vi cua tu*.