Perhaps you should try some spelling variations:
nam thuoc » nam thuc, nam thu, nha thuoc
thuoc van » thuoc va, thuc van, thuoc ban
van hanh » van thanh, ban hanh, van anh
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
ky dang » ky nang, ky danh
hieu ly » hieu ky, lieu ly, dieu ly
va ca » va cao, va cai, va cau

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: su sach ky dang ((le hoi) or (ma hoa)). hieu ly nam thuoc van hanh ((va ca) OR (va cac)) viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky dang ((le hoi) OR (ma hoa)). hieu ly nam thuoc van hanh ((va ca) OR (va cac)) viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky dang ((le hoi) or (ma hoa)). hieu ly nam thuoc van hanh ((va ca) OR (va cac)) viet".
• Adding a wildcard symbol may retrieve word variants: su sach ky dang ((le hoi) or (ma hoa)). hieu ly nam thuoc van hanh ((va ca) OR (va cac)) viet*.