Perhaps you should try some spelling variations:
ve triet » va trien, su triet
van hanh » van thanh, ban hanh, van anh
cam tuc » cam tu, nam thuc, dam thuc
hieu ve » hieu va, hieu van
tay hoi » tay ho, tao hoi, tay thai
may hoi » may thoi, mai hoi, may hmi
ky mang » ky nang, ke mang, ky dang
sac ky » cac ky, sai ky
su sac » su sach, su cac, su xac
vi ve » va ve, gi ve, ve ve

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

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