Perhaps you should try some spelling variations:
hieu vien » hieu viec, thieu nien, hieu tieng
hieu hien » bieu hien, dieu hien, chieu chien
dang xay » dang van, van xay
su triet » su tien, ve triet
hanh va » hang va, hanh vi
va hanh » van hanh, va thanh, va danh
so sach » so sanh, bo sach, co sach
sach ky » sac ky, sach y, sach ty
xay hoi » xa hoi, tay hoi, cay phoi
ky dang » ky nang, ky danh
su viet » so viet
cac tu » cac thu, cach tu, cac du

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: so sach ky dang xay hoi. ((hieu vien) OR (hieu hien)) cac tu va hanh va ((su triet) or (su viet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ky dang xay hoi. ((hieu vien) OR (hieu hien)) cac tu va hanh va ((su triet) OR (su viet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach ky dang xay hoi. ((hieu vien) OR (hieu hien)) cac tu va hanh va ((su triet) or (su viet))".
• Adding a wildcard symbol may retrieve word variants: so sach ky dang xay hoi. ((hieu vien) OR (hieu hien)) cac tu va hanh va ((su triet) or (su viet))*.