Perhaps you should try some spelling variations:
van thanh » ban thanh, van tuan
nam thuc » nam thuoc, am thuc, nam tu
van hanh » ban hanh, van anh, van ban
tang mai » tang ma, tang tai, lang mai
ky tang » ky nang, ky dang, kho tang
mai hoi » mai khoi, dai hoi, lai hoi
hieu ve » hieu va, hieu van
vi cua » vai cua, di cua
vu sac » vu sach, vu san, va sac
sac ky » cac ky, sai ky
cua te » cua tu

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

• Performing a fuzzy search may retrieve terms with similar spellings: vu sac ky tang mai hoi. hieu ve ((nam thuc) or (nam thu)) ((van hanh) or (van thanh)) vi cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sac ky tang mai hoi. hieu ve ((nam thuc) OR (nam thu)) ((van hanh) OR (van thanh)) vi cua te.
• Adding a wildcard symbol may retrieve word variants: vu sac ky tang mai hoi. hieu ve ((nam thuc) or (nam thu)) ((van hanh) or (van thanh)) vi cua te*.