Perhaps you should try some spelling variations:
can thiet » dan thiet, cac thiet, cad thiet
cham xuc » cam xuc, chat xuc, cham soc
van hanh » van thanh, ban hanh, van anh
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
ky sang » ky nang, ky dang, ky tang
sang ma » tang ma, nang ma, sang tao
hieu ve » hieu va, hieu van
ve cham » va cham, ve chat, vu cham
va hanh » va thanh, va danh, ban hanh
ma hoi » mai hoi, xa hoi, ma hoa
vi can » voi can, vi van, i can

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ky sang ma 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 sach ky sang ma hoi. hieu ve cham xuc ((va hanh) OR (van hanh)) vi can thiet.
• Adding a wildcard symbol may retrieve word variants: tu sach ky sang ma hoi. hieu ve cham xuc ((va hanh) or (van hanh)) vi can thiet*.