Perhaps you should try some spelling variations:
thuat sach » thuat lanh, thuat san
dang xay » dang van, van xay
hieu van » hieu va, thien van, lieu va
va triet » va thiet, va trien, ve triet
hieu ve » hieu va
lang xa » lang ha, lang van
cac tuc » cac toc, cac tu, cac tac
va hang » van hang, va nang, va lang
hang di » hang doi, hang vi, hang dien
tuc va » thuc va, truc va, tuc xa
di va » dai va, di vao, doi va

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

• Performing a fuzzy search may retrieve terms with similar spellings: thuat sach y ((lang xa) or (dang xay)) hoi. ((hieu ve) OR (hieu van)) cac tuc va hang di va triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuat sach y ((lang xa) OR (dang xay)) hoi. ((hieu ve) OR (hieu van)) cac tuc va hang di va triet*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuat sach y ((lang xa) or (dang xay)) hoi. ((hieu ve) OR (hieu van)) cac tuc va hang di va triet*".