Perhaps you should try some spelling variations:
va triet » va thiet, va trien, ve triet
van hanh » van thanh, ban hanh, van anh
nam thuc » nam thuoc, am thuc, nam thu
cam thuc » am thuc, cam thu, can thuc
hieu van » hieu va, thien van, lieu va
sach vu » sach tu, sach uu, sach xu
sach va » sach xa, sach ha, sach dao
x hoi » xa hoi, o hoi, x ho
vi va » vi van, vai va, vu va

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

• Performing a fuzzy search may retrieve terms with similar spellings: su ((sach vu) or (sach va)) nang x hoi. hieu van ((cam thuc) or (nam thuc)) van hanh vi va triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach vu) OR (sach va)) nang x hoi. hieu van ((cam thuc) OR (nam thuc)) van hanh vi va triet.
• Adding a wildcard symbol may retrieve word variants: su ((sach vu) or (sach va)) nang x hoi. hieu van ((cam thuc) or (nam thuc)) van hanh vi va triet*.