Perhaps you should try some spelling variations:
ban hanh » ban hang
nhan luc » nang luc
luc ban » duc ban, cuc ban, luc bat
va nhan » van nhan, ca nhan, va phan
tu sach » thu sach, su sach, te sach
va nang » van nang, da nang, cam nang
va sang » van sang, vua sang, va lang
hieu va » lieu va, hieu qua
ma hoi » mai hoi, xa hoi, ma hoa
ke ve » ke va, ke he, ke vi

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ((va sang) or (va nang)) ma hoi. hieu va nhan luc ban hanh ((ke ve) OR (de ve)) triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((va sang) OR (va nang)) ma hoi. hieu va nhan luc ban hanh ((ke ve) OR (de ve)) triet*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((va sang) or (va nang)) ma hoi. hieu va nhan luc ban hanh ((ke ve) OR (de ve)) triet*".