Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
cua triet » cua viet, su triet, va triet
vu khach » vu khanh, vu khac, vay khach
thuc ban » thuoc ban, thuc dan, thu ban
thanh va » thanh van, hanh va, thanh ha
cua tre » cua te, cuu tre, dua tren
y nang » ky nang, ly nang, v nang
ve nam » he nam, va nam, te nam
le nam » ly nam, he nam, le na
x hoi » xa hoi, o hoi, x ho

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 x hoi. hieu ((ve nam) OR (le nam)) thuc ban thanh va ((cua tre) or (cua triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu khach y nang x hoi. hieu ((ve nam) OR (le nam)) thuc ban thanh va ((cua tre) OR (cua triet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu khach y nang x hoi. hieu ((ve nam) OR (le nam)) thuc ban thanh va ((cua tre) or (cua triet))".
• Adding a wildcard symbol may retrieve word variants: vu khach y nang x hoi. hieu ((ve nam) OR (le nam)) thuc ban thanh va ((cua tre) or (cua triet))*.