Perhaps you should try some spelling variations:
cua viet » ca viet, hoa viet, cua vat
lao khoa » lo khoa, da khoa, ly khoa
nam thuc » nam thuoc, am thuc, nam thu
hieu le » hieu ve, hieu he, hieu ly
va hanh » van hanh, va thanh, ban hanh
va danh » va dinh, va dan, dia danh
ky dang » ky danh
doi cua » dai cua, hoi cua
le nam » ly nam, he nam, le na
su sac » su sach, su cac, su xac

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 sac ((ky dang) OR (ky nang)) lao khoa. hieu le nam thuc ((va hanh) OR (va danh)) doi cua viet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sac ((ky dang) OR (ky nang)) lao khoa. hieu le nam thuc ((va hanh) or (va danh)) doi cua viet~".
• Adding a wildcard symbol may retrieve word variants: su sac ((ky dang) OR (ky nang)) lao khoa. hieu le nam thuc ((va hanh) or (va danh)) doi cua viet*.