Perhaps you should try some spelling variations:
sang thao » sang tao, sang than, rang thao
thao khoa » thai khoa, toan khoa, pham khoa
cua viet » ca viet, hoa viet, cua vat
ky sang » ky nang, ky dang, ky tang
hieu le » hieu ve, hieu he, hieu ly
va hanh » van hanh, va thanh, ban hanh
va danh » va dinh, va dan, dia danh
su sac » su sach, su cac, su xac
sac ky » cac ky, sai ky
di cua » dai cua, doi cua, de cua
le am » le ham, le nam, le a

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sac ky sang thao khoa. hieu le am thuc ((va hanh) or (va danh)) di cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sac ky sang thao khoa. hieu le am thuc ((va hanh) OR (va danh)) di cua viet.
• Adding a wildcard symbol may retrieve word variants: su sac ky sang thao khoa. hieu le am thuc ((va hanh) or (va danh)) di cua viet*.