Perhaps you should try some spelling variations:
dau tieng » dau tien, cau tieng, day tieng
hanh vai » hanh vi, hanh va, hanh tai
van hanh » van thanh, ban hanh, van anh
vai dau » va dau, van dau, xvii dau
cam thu » cac thu, ca thu, cam phu
hieu ve » hieu va, hieu van
sang ma » tang ma, sang tao, mang may
nang ma » tang ma, nang cao, mang may
can ky » van ky, dan ky, ban ky
tu can » tu ban, tu cac, thu canh

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu can ky ((sang ma) or (nang ma)) hoi. hieu ve ((cam thu) or (nam thu)) van hanh vai dau tieng~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu can ky ((sang ma) OR (nang ma)) hoi. hieu ve ((cam thu) OR (nam thu)) van hanh vai dau tieng.
• Adding a wildcard symbol may retrieve word variants: tu can ky ((sang ma) or (nang ma)) hoi. hieu ve ((cam thu) or (nam thu)) van hanh vai dau tieng*.