Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
van hanh » van thanh, ban hanh, van anh
hanh tai » thanh tai, hang tai, han tai
nang xa » nang x, lang xa, nang ma
nam duc » nam duoc, pham duc, nam thuc
duc van » duc va, duc tan, duc manh
tai cua » thai cua, tai cuc, tri cua
sai ky » sac 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: thu ((sai ky) or (cac ky)) nang xa hoi. hieu van nam duc van hanh tai cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu ((sai ky) OR (cac ky)) nang xa hoi. hieu van nam duc van hanh tai cua te.
• Adding a wildcard symbol may retrieve word variants: thu ((sai ky) or (cac ky)) nang xa hoi. hieu van nam duc van hanh tai cua te*.