Perhaps you should try some spelling variations:
sang mai » sang ma, sang tai, lang mai
nam thuc » nam thuoc, am thuc, nam thu
hieu le » hieu ve, hieu he, hieu ly
va hanh » van hanh, va thanh, ban hanh
su sach » so sach, vu sach
ky sang » ky nang, ky dang, ky tang
mai hoi » mai khoi, dai hoi, lai hoi
va danh » va dinh, va dan, dia danh
su sac » su cac, su xac
le nam » ly nam, he nam, le na
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 sac) OR (su sach)) ky sang mai hoi. hieu le nam thuc ((va hanh) or (va danh)) di cua vat~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sac) OR (su sach)) ky sang mai hoi. hieu le nam thuc ((va hanh) OR (va danh)) di cua vat.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sac) OR (su sach)) ky sang mai hoi. hieu le nam thuc ((va hanh) or (va danh)) di cua vat".
• Adding a wildcard symbol may retrieve word variants: ((su sac) OR (su sach)) ky sang mai hoi. hieu le nam thuc ((va hanh) or (va danh)) di cua vat*.