Perhaps you should try some spelling variations:
nam thuoc » nam thuc, nam thu, nha thuoc
cua viet » ca viet, hoa viet, cua vat
tao khoi » thao khoa, lao khoa, tao boi
va hanh » van hanh, va thanh, ban hanh
ky dang » ky nang, ky danh
tao hoi » tao boi, tay hoi, thao hoc
hieu le » hieu ve, hieu he, hieu ly
va danh » va dinh, va dan, dia danh
de cua » le cua, te cua, dieu cua
su sac » su sach, su cac, su xac
sac ky » cac ky, sai ky
le nam » ly nam, he nam, le na

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