Perhaps you should try some spelling variations:
van nhan » van phan, van thanh, danh nhan
nang xa » nang x, lang xa, nang ma
hieu va » lieu va, hieu qua
luu van » cuu van, luan van, luu hanh
sac ky » sai ky
va cao » va cac, va co, va dao
cua tu » cua tuc, cua su, cua te
cua cu » cua chu, cua cau, cua su

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu ((sac ky) or (cac ky)) nang xa hoi. hieu va cao luu van nhan vien ((cua tu) or (cua cu))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu ((sac ky) OR (cac ky)) nang xa hoi. hieu va cao luu van nhan vien ((cua tu) OR (cua cu)).
• Adding a wildcard symbol may retrieve word variants: thu ((sac ky) or (cac ky)) nang xa hoi. hieu va cao luu van nhan vien ((cua tu) or (cua cu))*.