Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
toc sach » hoc sach, doc sach, thuoc sach
dang xay » dang van, van xay
tai thuc » thai thuc, tri thuc, dai thuc
hieu va » lieu va, hieu qua
va hanh » van hanh, va thanh, ban hanh
va danh » va dinh, va dan, dia danh
via cua » gia cua, gian cua, giau cua
va tai » va tac, va tap

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 ((nang x) or (dang xay)) hoi. hieu va tai thuc ((va hanh) OR (va danh)) via cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach y ((nang x) OR (dang xay)) hoi. hieu va tai thuc ((va hanh) OR (va danh)) via cua triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach y ((nang x) or (dang xay)) hoi. hieu va tai thuc ((va hanh) OR (va danh)) via cua triet".
• Adding a wildcard symbol may retrieve word variants: toc sach y ((nang x) or (dang xay)) hoi. hieu va tai thuc ((va hanh) OR (va danh)) via cua triet*.