Perhaps you should try some spelling variations:
cac thuc » cach thuc, cac thu, can thuc
hieu van » hieu va, thien van, lieu va
su sach » so sach, vu sach
va dinh » van dinh, va kinh, va tinh
thuc va » thuc vat, thuc dan, thuc day
van cac » van hac, van cau, van bac
cao hoi » cau hoi, co hoi, cao hoc
so sanh » do sanh
y nang » ky nang, ly nang, v nang
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) OR (so sanh)) y nang cao hoi. hieu van cac thuc va dinh ((vi cua) OR (di cua)) tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sach) or (so sanh)) y nang cao hoi. hieu van cac thuc va dinh ((vi cua) OR (di cua)) tre~".
• Adding a wildcard symbol may retrieve word variants: ((su sach) or (so sanh)) y nang cao hoi. hieu van cac thuc va dinh ((vi cua) OR (di cua)) tre*.