Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
va triet » va thiet, va trien, ve triet
cua viet » ca viet, hoa viet, cua vat
tang xa » trang xa, tang ma, lang xa
hieu ve » hieu va, hieu van
ve cham » va cham, ve chat, vu cham
danh tu » anh tu, doanh thu
y tang » ky tang, 6 tang, 7 tang
loc va » hoc va
luc va » duc va, tuc va

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc sach y tang xa hoi. hieu ve cham ((loc va) or (luc va)) danh tu ((va triet) or (cua viet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach y tang xa hoi. hieu ve cham ((loc va) OR (luc va)) danh tu ((va triet) OR (cua viet)).
• Adding a wildcard symbol may retrieve word variants: toc sach y tang xa hoi. hieu ve cham ((loc va) or (luc va)) danh tu ((va triet) or (cua viet))*.