Perhaps you should try some spelling variations:
so triet » su triet, so thiet, bo triet
nang noi » nang doc
hieu van » hieu va, thien van, lieu va
sach ly » sach y, sach lo, sach ty
tu sach » thu sach, su sach, te sach
ly hang » ly quang
ca hoi » cau hoi, cua hoi, co hoi
luc va » duc va, loc va
tuc va » thuc va, truc va, tuc xa
noi so » noi bo, noi co

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ly hang ((ca hoi) OR (xa hoi)). hieu van nam ((luc va) or (tuc va)) nang noi so triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ly hang ((ca hoi) OR (xa hoi)). hieu van nam ((luc va) OR (tuc va)) nang noi so triet*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ly hang ((ca hoi) OR (xa hoi)). hieu van nam ((luc va) or (tuc va)) nang noi so triet*".