Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
ban hanh » ban hang
va danh » va dinh, va dan, va hanh
hac xuc » chat xuc
van hac » van hoc, van ha, van hai
sach ty » sach y, sach tu, sach thu
su sach » so sach, vu sach
mai hoi » mai khoi, dai hoi, lai hoi
ty nang » ky nang, ty xang, ty hang
su viet » so viet
ma hoi » xa hoi, ma hoa, me hoi
vi su » va su, ve su, ki su

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

• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ty nang ((ma hoi) OR (mai hoi)). hieu van hac xuc ((va danh) OR (ban hanh)) vi su viet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ty nang ((ma hoi) OR (mai hoi)). hieu van hac xuc ((va danh) or (ban hanh)) vi su viet~".
• Adding a wildcard symbol may retrieve word variants: su sach ty nang ((ma hoi) OR (mai hoi)). hieu van hac xuc ((va danh) or (ban hanh)) vi su viet*.