Perhaps you should try some spelling variations:
va triet » va thiet, va trien, ve triet
cua viet » ca viet, hoa viet, cua vat
dang xay » dang van, van xay
sach ky » sac ky, sach y, sach ty
hanh va » hang va, hanh vi
va hanh » van hanh, va thanh, va danh
hai tuc » thai tuc, hai cuc, thai thuc
te sach » toc sach
hieu va » lieu va, hieu qua
nang xa » nang x, lang xa, nang ma
tuc va » thuc va, truc va, tuc xa
va hai » van hai, va chai, va khai

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 ky ((nang xa) or (dang xay)) hoi. hieu va hai tuc va hanh va ((cua viet) or (va triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ky ((nang xa) OR (dang xay)) hoi. hieu va hai tuc va hanh va ((cua viet) OR (va triet)).
• Adding a wildcard symbol may retrieve word variants: te sach ky ((nang xa) or (dang xay)) hoi. hieu va hai tuc va hanh va ((cua viet) or (va triet))*.