Perhaps you should try some spelling variations:
hieu vuc » hieu luc, hieu tuc, hieu thuc
vuc nang » cuc nang, vu nang, chuc nang
va tinh » may tinh
nang xa » nang x, lang xa, nang ma
sach va » sach xa, sach ha, sach dao
sach v » sach y, sach 2, sach vay
luc va » duc va, tuc va, loc va
hai co » phai co, hai con, hoi co

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

• Performing a fuzzy search may retrieve terms with similar spellings: su ((sach v) or (sach va)) nang xa hoi. hieu vuc nang luc va tinh ((hai co) OR (mai co)) viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach v) OR (sach va)) nang xa hoi. hieu vuc nang luc va tinh ((hai co) OR (mai co)) viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su ((sach v) or (sach va)) nang xa hoi. hieu vuc nang luc va tinh ((hai co) OR (mai co)) viet".
• Adding a wildcard symbol may retrieve word variants: su ((sach v) or (sach va)) nang xa hoi. hieu vuc nang luc va tinh ((hai co) OR (mai co)) viet*.