Perhaps you should try some spelling variations:
dam thuc » am thuc, dan thuc, nam thuc
van hanh » van thanh, ban hanh, van anh
ky dang » ky nang, ky danh
mai hoi » mai khoi, lai hoi, mai doi
dai hoi » dai hoc, dai hai, dai moi
hieu ve » hieu va, hieu van
su xac » pu xac, su cac
xac ky » cac ky, sac ky, bac ky
vi hoa » voi hoa, vi hoc, va hoa

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

• Performing a fuzzy search may retrieve terms with similar spellings: su xac ky dang ((mai hoi) OR (dai hoi)). hieu ve ((dam thuc) or (cam xuc)) van hanh vi hoa viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su xac ky dang ((mai hoi) OR (dai hoi)). hieu ve ((dam thuc) OR (cam xuc)) van hanh vi hoa viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su xac ky dang ((mai hoi) OR (dai hoi)). hieu ve ((dam thuc) or (cam xuc)) van hanh vi hoa viet".
• Adding a wildcard symbol may retrieve word variants: su xac ky dang ((mai hoi) OR (dai hoi)). hieu ve ((dam thuc) or (cam xuc)) van hanh vi hoa viet*.