Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
va thanh » gia thanh, ban thanh, va tinh
gia cua » gian cua, giau cua, gia cuc
va hanh » van hanh, va danh, ban hanh
cac duc » cac du, cao duc, cac dac
hieu va » lieu va, hieu qua
sach ky » sac ky, sach ty, sach kem
nang o » nang co, nang ho, nang ro
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: tu ((sach ky) or (sach y)) nang o hoi. hieu va cac duc ((va hanh) OR (va thanh)) gia cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ky) OR (sach y)) nang o hoi. hieu va cac duc ((va hanh) OR (va thanh)) gia cua triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach ky) or (sach y)) nang o hoi. hieu va cac duc ((va hanh) OR (va thanh)) gia cua triet".
• Adding a wildcard symbol may retrieve word variants: tu ((sach ky) or (sach y)) nang o hoi. hieu va cac duc ((va hanh) OR (va thanh)) gia cua triet*.