Perhaps you should try some spelling variations:
ban hanh » ban hang
cua viet » ca viet, hoa viet, cua vat
nang ma » tang ma, sang ma, nang cao
hieu he » hieu ve, hiem he, hieu le
va danh » va dinh, va dan, va hanh
su sai » su tai, su hai, su dai
sai ky » sac ky
ma hoi » mai hoi, xa hoi, ma hoa
di cua » dai cua, doi cua, de cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sai ky nang ma hoi. hieu he ((am thuc) or (nam thu)) ((ban hanh) or (va danh)) di cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sai ky nang ma hoi. hieu he ((am thuc) OR (nam thu)) ((ban hanh) OR (va danh)) di cua viet.
• Adding a wildcard symbol may retrieve word variants: su sai ky nang ma hoi. hieu he ((am thuc) or (nam thu)) ((ban hanh) or (va danh)) di cua viet*.