Perhaps you should try some spelling variations:
va triet » va thiet, va trien, ve triet
hanh va » hang va, hanh vi
hanh vu » hanh vi, hanh tu, hanh ve
cau duc » cao duc, cau luc, chu duc
hieu ve » hieu va, hieu van
vu khac » vu kham, vu khanh, bui khac
sang ma » tang ma, sang tao, mang may
nang ma » tang ma, nang cao, mang may
ve cau » ke cau, va cau, ve cac

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

• Performing a fuzzy search may retrieve terms with similar spellings: vu khac y ((nang ma) OR (sang ma)) hoi. hieu ve cau duc va ((hanh vu) or (hanh va)) va triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu khac y ((nang ma) OR (sang ma)) hoi. hieu ve cau duc va ((hanh vu) OR (hanh va)) va triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu khac y ((nang ma) OR (sang ma)) hoi. hieu ve cau duc va ((hanh vu) or (hanh va)) va triet".
• Adding a wildcard symbol may retrieve word variants: vu khac y ((nang ma) OR (sang ma)) hoi. hieu ve cau duc va ((hanh vu) or (hanh va)) va triet*.