Perhaps you should try some spelling variations:
vu khach » vu khanh, vu khac, vay khach
ve triet » su triet
va trien » va truyen, va thiet, va tuyen
hieu ve » hieu va, hieu van
cau luc » cau truc, cau phuc
hanh vu » hanh vi, hanh tu, hanh ve
hanh va » hang va, hanh vi
ve cau » ke cau, va cau, ve cac
luc va » duc va, tuc va, loc va
y nang » ky nang, ly nang, v nang
nang o » nang co, nang ho, nang ro
o hoi » co hoi, o hoc, o hai

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

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