Perhaps you should try some spelling variations:
cua triet » su triet, va triet
toc sach » hoc sach, doc sach, thuoc sach
cua viet » ca viet, hoa viet, cua vat
x quang » xa quang, _ quang, le quang
hieu va » lieu va, hieu qua
cac luc » cau luc, coc luc, cac nuoc
va danh » va dinh, va dan, va hanh
danh vi » hanh vi, dinh vi, danh di
luc va » duc va, tuc va, loc 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 ((x quang) or (vu quang)) xa hoi. hieu va cac luc va danh vi ((cua triet) OR (cua viet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ((x quang) OR (vu quang)) xa hoi. hieu va cac luc va danh vi ((cua triet) OR (cua viet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ((x quang) or (vu quang)) xa hoi. hieu va cac luc va danh vi ((cua triet) OR (cua viet))".
• Adding a wildcard symbol may retrieve word variants: toc sach ((x quang) or (vu quang)) xa hoi. hieu va cac luc va danh vi ((cua triet) OR (cua viet))*.