Perhaps you should try some spelling variations:
danh thai » anh thai, dang thai, dinh thai
va triet » va thiet, va trien, ve triet
hieu van » thien van, lieu va, hieu ve
sach tu » sach thu, cach tu, sach ty
thai va » thai van
truc va » thuc va, thuc vat, trung va
su sach » so sach, vu sach
nang xa » nang x, lang xa, nang ma
hieu va » lieu va, hieu qua
tu nang » tru nang, tu nong, tu nano
tuc va » thuc va, tuc xa, duc 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 tu nang xa hoi. ((hieu van) or (hieu va)) hac ((tuc va) OR (truc va)) danh thai va triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach tu nang xa hoi. ((hieu van) OR (hieu va)) hac ((tuc va) OR (truc va)) danh thai va triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach tu nang xa hoi. ((hieu van) or (hieu va)) hac ((tuc va) OR (truc va)) danh thai va triet".
• Adding a wildcard symbol may retrieve word variants: su sach tu nang xa hoi. ((hieu van) or (hieu va)) hac ((tuc va) OR (truc va)) danh thai va triet*.