Perhaps you should try some spelling variations:
hieu van » thien van, lieu va, hieu ve
va thanh » gia thanh, ban thanh, va tinh
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
nang ma » tang ma, sang ma, nang cao
hieu va » lieu va, hieu qua
cac loc » cac lop, cac toc, cac hoc
ma hoi » mai hoi, xa hoi, ma hoa
loc va » hoc va, luc va
vi cua » vai cua
di cua » dai cua, doi cua, de cua

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 ky nang ma hoi. ((hieu van) OR (hieu va)) cac loc va thanh ((vi cua) OR (di cua)) tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky nang ma hoi. ((hieu van) or (hieu va)) cac loc va thanh ((vi cua) OR (di cua)) tre~".
• Adding a wildcard symbol may retrieve word variants: su sach ky nang ma hoi. ((hieu van) or (hieu va)) cac loc va thanh ((vi cua) OR (di cua)) tre*.