Perhaps you should try some spelling variations:
dang xay » dang van, van xay
tai thuc » thai thuc, tri thuc, dai thuc
hanh via » hanh vi, hanh va, anh va
su triet » su viet, su tien, ve triet
te sach » toc sach
hieu va » lieu va, hieu qua
thuc va » thuc vat, thuc dan, thuc day
va hanh » van hanh, va thanh, va danh
va tai » va tac, va tap
via su » va su, gia su

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 x) or (dang xay)) hoi. hieu va tai thuc va hanh via su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach y ((nang x) OR (dang xay)) hoi. hieu va tai thuc va hanh via su triet.
• Adding a wildcard symbol may retrieve word variants: te sach y ((nang x) or (dang xay)) hoi. hieu va tai thuc va hanh via su triet*.