Perhaps you should try some spelling variations:
cau thuc » cau truc, cuu thuc, can thuc
hieu va » lieu va, hieu qua
va hanh » van hanh, va thanh, va danh
thuc va » thuc vat, thuc dan, thuc day
tu sach » thu sach, su sach, te sach
hieu ve » hieu van
nang xa » nang x, lang xa, nang ma
sach v » sach va, sach y, sach 2
v nang » va nang, vu nang, van nang
di cua » dai cua, doi cua, do cua
de cua » le cua, te cua, dieu 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: tu sach v nang xa hoi. ((hieu ve) OR (hieu va)) cau thuc va hanh ((di cua) OR (de cua)) triet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach v nang xa hoi. ((hieu ve) or (hieu va)) cau thuc va hanh ((di cua) OR (de cua)) triet~".
• Adding a wildcard symbol may retrieve word variants: tu sach v nang xa hoi. ((hieu ve) or (hieu va)) cau thuc va hanh ((di cua) OR (de cua)) triet*.