Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
cua triet » cua viet, su triet
va thanh » gia thanh, va tinh, le thanh
va triet » va thiet, va trien, ve triet
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
hieu va » lieu va, hieu qua
cau duc » cao duc, cau luc, chu duc
nang o » nang co, nang ho, nang ro
va cau » van cau, va cac, va dau
o hoi » co hoi, o hoc, o hai

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