Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
thai thuc » thai thuy, thai tuc, tham thuc
dang xay » dang van, van xay
va thanh » gia thanh, ban thanh, va tinh
hieu va » lieu va, hieu qua
va thai » van thai, va tai, va tham
va hanh » van hanh, va danh, ban hanh
tu sach » thu sach, su sach, te sach
va cua » va chua, via cua, ca cua

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