Perhaps you should try some spelling variations:
sang mai » sang ma, sang tai, lang mai
van hanh » van thanh, ban hanh, van ban
van anh » van thanh, tuan anh, van minh
ky sang » ky nang, ky dang, ky tang
mai hoi » mai khoi, dai hoi, lai hoi
hieu ve » hieu va, hieu van
va danh » va dinh, va dan, va hanh
su sac » su sach, su cac, su xac
sac ky » cac ky, sai ky
di cua » dai cua, doi cua, de cua
ve am » va am

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 mai hoi. hieu ve am thuc ((((van hanh) or (van anh))) or (va danh)) di cua vat~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sac ky sang mai hoi. hieu ve am thuc ((((van hanh) OR (van anh))) OR (va danh)) di cua vat.
• Adding a wildcard symbol may retrieve word variants: su sac ky sang mai hoi. hieu ve am thuc ((((van hanh) or (van anh))) or (va danh)) di cua vat*.