Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
su sach » so sach, vu sach
nang xa » nang x, lang xa, nang ma
qua hai » qua hoat
hai duc » hoai duc, mai duc, ha duc
duc van » duc va, duc tan, duc manh
vi cau » ve cau, di cau, viet cau
va cau » van cau, va cac, 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) or (vu bach)) ky nang xa hoi. hieu qua hai duc van hanh ((vi cau) OR (va cau)) treo~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (vu bach)) ky nang xa hoi. hieu qua hai duc van hanh ((vi cau) OR (va cau)) treo.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sach) or (vu bach)) ky nang xa hoi. hieu qua hai duc van hanh ((vi cau) OR (va cau)) treo".
• Adding a wildcard symbol may retrieve word variants: ((su sach) or (vu bach)) ky nang xa hoi. hieu qua hai duc van hanh ((vi cau) OR (va cau)) treo*.