Perhaps you should try some spelling variations:
thien van » thi van
ban thanh » ban hanh, ban hang
hieu van » hieu va, lieu va, hieu ve
thanh ca » thanh cha, thanh cac, thanh ha
te sach » toc sach
ky lang » ky nang, ky dang, tay lang
ky tang » ky nang, ky dang, kho tang
cac duc » cac du, cao duc, cac dac
duc ban » duc tan, duc van, dua ban
ca hoa » cau hoa, cam hoa, cai hoa

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sach ((ky lang) or (ky tang)) xa hoi. ((hieu van) OR (thien van)) cac duc ban thanh ca hoa viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ((ky lang) OR (ky tang)) xa hoi. ((hieu van) OR (thien van)) cac duc ban thanh ca hoa viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ((ky lang) or (ky tang)) xa hoi. ((hieu van) OR (thien van)) cac duc ban thanh ca hoa viet".
• Adding a wildcard symbol may retrieve word variants: te sach ((ky lang) or (ky tang)) xa hoi. ((hieu van) OR (thien van)) cac duc ban thanh ca hoa viet*.