Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
lang hoa » hang hoa, lang ha, nang hoa
nam thuc » nam thuoc, am thuc, nam thu
su triet » su viet, su tien, ve triet
ky lang » ky nang, ky dang, ky tang
hoa hoi » khoa hoi, hoa hoc, hoa doi
hieu he » hieu ve, hiem he, hieu le
va hanh » va thanh, va danh, ban hanh
tu sac » tu sach, tu cac, tu san
sac ky » cac ky, sai ky
he nam » ha nam, nghe nam
kien » bien, vien, tien

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sac ky lang hoa hoi. hieu he nam thuc ((va hanh) OR (van hanh)) ve ((su triet) or (su kien))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sac ky lang hoa hoi. hieu he nam thuc ((va hanh) OR (van hanh)) ve ((su triet) OR (su kien)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sac ky lang hoa hoi. hieu he nam thuc ((va hanh) OR (van hanh)) ve ((su triet) or (su kien))".
• Adding a wildcard symbol may retrieve word variants: tu sac ky lang hoa hoi. hieu he nam thuc ((va hanh) OR (van hanh)) ve ((su triet) or (su kien))*.