Perhaps you should try some spelling variations:
can thiet » dan thiet, cac thiet, cad thiet
cham xuc » cam xuc, chat xuc, cham soc
hieu va » lieu va, hieu qua
va hanh » van hanh, va thanh, va danh
cao hoi » cau hoi, co hoi, cao hoc
hieu ve » hieu van
vi can » voi can, vi van, i can
xuc va » duc va, tuc va, luc va
sac ky » cac ky, sai ky

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu ((sac ky) or (sach y)) nang cao hoi. ((hieu ve) OR (hieu va)) cham xuc va hanh vi can thiet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sac ky) OR (sach y)) nang cao hoi. ((hieu ve) OR (hieu va)) cham xuc va hanh vi can thiet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sac ky) or (sach y)) nang cao hoi. ((hieu ve) OR (hieu va)) cham xuc va hanh vi can thiet".
• Adding a wildcard symbol may retrieve word variants: tu ((sac ky) or (sach y)) nang cao hoi. ((hieu ve) OR (hieu va)) cham xuc va hanh vi can thiet*.