Perhaps you should try some spelling variations:
hieu viec » nhieu viec, hieu ve, sieu viet
hieu vien » hieu hien, thieu nien, hieu tieng
cac nuoc » cap nuoc, hoc nuoc, dat nuoc
su triet » su tien, ve triet
van hanh » van thanh, ban hanh, van anh
nuoc van » nuoc va, nuoc san, luoc van
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
tang xa » trang xa, tang ma, lang xa
ky tang » ky nang, ky dang, kho tang
su viet » so viet

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

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