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

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

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