Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, thieu nien
vien dat » vien dai, vien da, viec dat
nuoc ban » nuoc san, quoc ban, buoc ban
ban hang » ngan hang
su triet » su tien, ve triet
su sach » so sach, vu sach
ky tang » ky dang, kho tang, ky trong
hang vi » hang va, hanh vi, hang di
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) OR (ky nang)) xa hoi. hieu vien dat nuoc ban hang vi ((su triet) or (su viet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ((ky tang) OR (ky nang)) xa hoi. hieu vien dat nuoc ban hang vi ((su triet) OR (su viet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ((ky tang) OR (ky nang)) xa hoi. hieu vien dat nuoc ban hang vi ((su triet) or (su viet))".
• Adding a wildcard symbol may retrieve word variants: su sach ((ky tang) OR (ky nang)) xa hoi. hieu vien dat nuoc ban hang vi ((su triet) or (su viet))*.