Perhaps you should try some spelling variations:
va triet » va thiet, va trien, ve triet
mai khoi » mai khoa, tai khoa, cac khoi
hanh vai » hanh vi, hanh tai, hanh van
hieu van » hieu va, thien van, lieu va
mai hoi » dai hoi, lai hoi, mai doi
van cam » van nam, van lam, van cau
cam duc » cam xuc, cao duc, pham duc
ky tang » ky nang, ky dang, kho tang
hanh va » hang va, hanh vi
xac ky » cac ky, sac ky, bac ky
pu xac » su xac

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

• Performing a fuzzy search may retrieve terms with similar spellings: pu xac ky tang ((mai hoi) OR (mai khoi)). hieu van cam duc va ((hanh vai) or (hanh va)) va triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: pu xac ky tang ((mai hoi) OR (mai khoi)). hieu van cam duc va ((hanh vai) OR (hanh va)) va triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "pu xac ky tang ((mai hoi) OR (mai khoi)). hieu van cam duc va ((hanh vai) or (hanh va)) va triet".
• Adding a wildcard symbol may retrieve word variants: pu xac ky tang ((mai hoi) OR (mai khoi)). hieu van cam duc va ((hanh vai) or (hanh va)) va triet*.