Perhaps you should try some spelling variations:
ve triet » va trien, su triet
cao tang » cao dang
van hanh » van thanh, ban hanh, van anh
sach cao » sach dao, sach cap, mach cao
cam tuc » cam tu, nam thuc, dam thuc
su sach » so sach, vu sach
hieu ve » hieu va, hieu van
ma hoi » mai hoi, xa hoi, me hoi
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 sach cao tang ((ma hoi) or (ma hoa)). 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 sach cao tang ((ma hoi) OR (ma hoa)). hieu ve ((cam tuc) OR (cam xuc)) van hanh vi ve triet.
• Adding a wildcard symbol may retrieve word variants: su sach cao tang ((ma hoi) or (ma hoa)). hieu ve ((cam tuc) or (cam xuc)) van hanh vi ve triet*.