Perhaps you should try some spelling variations:
va triet » va trien, ve triet, cua triet
nam thuc » nam thuoc, am thuc, nam thu
su sach » so sach, vu sach
va hanh » van hanh, va thanh, va danh
nang xa » nang x, lang xa, mang xa
nang ma » tang ma, sang ma, nang cao
hanh va » hang va, hanh vi
hieu ve » hieu va, hieu van
sach ky » sac ky, sach y, sach ty
thuc va » thuc vat, thuc dan, thuc day
ve nam » he nam, va nam, le nam
thiet » thieu

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 xa) OR (nang ma)) hoi. hieu ve nam thuc va hanh va ((va triet) OR (va thiet))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky ((nang xa) OR (nang ma)) hoi. hieu ve nam thuc va hanh va ((va triet) or (va thiet))~".
• Adding a wildcard symbol may retrieve word variants: su sach ky ((nang xa) OR (nang ma)) hoi. hieu ve nam thuc va hanh va ((va triet) or (va thiet))*.