Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
hanh tai » thanh tai, hang tai, han tai
cua viet » ca viet, hoa viet, cua vat
nang co » nang cao, nang doc, nang noi
duc van » duc va, duc tan, duc manh
tai cua » thai cua, tai cuc, tri cua
te sac » te sach, te cac, te san
sac ky » cac ky, sai ky
co hoi » co hoc, co loi
ve cac » vien cac

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sac ky nang co hoi. hieu ((ve cac) or (va cac)) duc van hanh tai cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sac ky nang co hoi. hieu ((ve cac) OR (va cac)) duc van hanh tai cua viet.
• Adding a wildcard symbol may retrieve word variants: te sac ky nang co hoi. hieu ((ve cac) or (va cac)) duc van hanh tai cua viet*.