Perhaps you should try some spelling variations:
va triet » va thiet, va trien, ve triet
may nang » may nong, ky nang, cam nang
hanh sua » hinh su, hanh va, hanh tu
van hanh » van thanh, ban hanh, van anh
duc van » duc va, duc tan, duc manh
cam duc » cam xuc, cao duc, pham duc
hieu ve » hieu va, hieu van
su sach » so sach, vu sach
va nang » van nang, da nang, cam nang
ve cam » ve cham, ve cac, va cam
sua va » suat va, vua va, xua va
o hoi » co hoi, o hai, o hoa
o hoc » co hoc, mo hoc, so hoc

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 ((may nang) or (va nang)) ((o hoi) OR (o hoc)). hieu ve cam duc van hanh sua va triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ((may nang) OR (va nang)) ((o hoi) OR (o hoc)). hieu ve cam duc van hanh sua va triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ((may nang) or (va nang)) ((o hoi) OR (o hoc)). hieu ve cam duc van hanh sua va triet".
• Adding a wildcard symbol may retrieve word variants: su sach ((may nang) or (va nang)) ((o hoi) OR (o hoc)). hieu ve cam duc van hanh sua va triet*.