Perhaps you should try some spelling variations:
va hanh » van hanh, va thanh, va danh
hieu ve » hieu va, hieu van
su sach » so sach, vu sach
nang xa » nang x, nang ma, mang xa
lang xa » lang ha, dang xay, lang van
cau luc » cau truc, cau phuc
ve cau » ke cau, va cau, ve cac
luc va » duc va, tuc va, loc va
vai va » mai va, hai va, lai va
dai va » mai va

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 y ((nang xa) or (lang xa)) hoi. hieu ve cau luc va hanh ((vai va) OR (dai va)) triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach y ((nang xa) OR (lang xa)) hoi. hieu ve cau luc va hanh ((vai va) OR (dai va)) triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach y ((nang xa) or (lang xa)) hoi. hieu ve cau luc va hanh ((vai va) OR (dai va)) triet".
• Adding a wildcard symbol may retrieve word variants: su sach y ((nang xa) or (lang xa)) hoi. hieu ve cau luc va hanh ((vai va) OR (dai va)) triet*.