Perhaps you should try some spelling variations:
hieu vien » hieu hien, thieu nien, hieu tieng
hieu viec » nhieu viec, hieu ve, sieu viet
cac nuoc » cap nuoc, hoc nuoc, dat nuoc
su triet » su viet, 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
nang xa » nang x, lang xa, nang ma
su tien » su kien, su hien, tu tieng

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