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 » chat xuc, cham soc, pham duc
sang ma » tang ma, nang ma, sang tao
hieu ve » hieu va, hieu van
sach ky » sac ky, sach y, sach ty
va hanh » va thanh, va danh, ban hanh
ky sang » ky nang, ky dang, ky tang
tu sach » thu sach, su sach, te sach
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) OR (cam 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) OR (cam xuc)) ((va hanh) OR (van hanh)) vi can thiet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky sang ma hoi. hieu ve ((cham xuc) OR (cam 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) OR (cam xuc)) ((va hanh) or (van hanh)) vi can thiet*.