Perhaps you should try some spelling variations:
thai thuc » thai thuy, thai tuc, tham thuc
cua triet » cua viet, su triet, va triet
dang xay » dang van, van xay
hieu van » hieu va, thien van, lieu va
hai tuc » thai tuc, hai cuc, hai huoc
hanh va » hang va, hanh vi
va hanh » van hanh, va thanh, va danh
te sach » toc sach
nang ma » tang ma, sang ma, nang cao
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: te sach y ((nang ma) or (dang xay)) hoi. hieu van ((hai tuc) OR (thai thuc)) va hanh va cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach y ((nang ma) OR (dang xay)) hoi. hieu van ((hai tuc) OR (thai thuc)) va hanh va cua triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach y ((nang ma) or (dang xay)) hoi. hieu van ((hai tuc) OR (thai thuc)) va hanh va cua triet".
• Adding a wildcard symbol may retrieve word variants: te sach y ((nang ma) or (dang xay)) hoi. hieu van ((hai tuc) OR (thai thuc)) va hanh va cua triet*.