Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
su triet » su viet, ve triet
dang xay » dang van, van xay
hai tuc » thai tuc, hai cuc, thai thuc
hanh va » hang va, hanh vi
va hanh » van hanh, va thanh, va danh
su tien » su kien, su hien, tu tieng
sach ky » sac ky, sach y, sach ty
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: thu sach ky ((nang xa) or (dang xay)) hoi. hieu va hai tuc va hanh va ((su triet) OR (su tien))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ky ((nang xa) OR (dang xay)) hoi. hieu va hai tuc va hanh va ((su triet) OR (su tien)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ky ((nang xa) or (dang xay)) hoi. hieu va hai tuc va hanh va ((su triet) OR (su tien))".
• Adding a wildcard symbol may retrieve word variants: thu sach ky ((nang xa) or (dang xay)) hoi. hieu va hai tuc va hanh va ((su triet) OR (su tien))*.