Perhaps you should try some spelling variations:
can thiet » dan thiet, cac thiet, cad thiet
van hanh » van thanh, ban hanh, van anh
cham xuc » cam xuc, chat xuc, cham soc
dang mam » dang nam, dang mau, dang mat
va hanh » va thanh, va danh, ban hanh
ve cham » va cham, ve chat, vu cham
hieu ve » hieu va, hieu van
dang ma » dang mau, dang mat, tang ma
sac ky » cac ky, sai ky
vi can » voi can, vi van, i can
tu sac » tu sach, tu cac, tu san

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