Perhaps you should try some spelling variations:
cua triet » su triet, va triet
cua viet » ca viet, hoa viet, cua vat
cham duc » pham duc, cham soc, pham duy
sach thu » sach thue, sach thieu, sach tham
hanh ve » hanh vi, hanh va, hanh kem
va hanh » van hanh, va thanh, va danh
va cham » va chat, va tham
sach tu » cach tu, sach ty, sach uu
hieu va » lieu va, hieu qua
cong o » cong so, cong co, cong bo
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: te ((sach tu) or (sach thu)) cong o hoi. hieu va cham duc va hanh ve ((cua triet) OR (cua viet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te ((sach tu) OR (sach thu)) cong o hoi. hieu va cham duc va hanh ve ((cua triet) OR (cua viet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "te ((sach tu) or (sach thu)) cong o hoi. hieu va cham duc va hanh ve ((cua triet) OR (cua viet))".
• Adding a wildcard symbol may retrieve word variants: te ((sach tu) or (sach thu)) cong o hoi. hieu va cham duc va hanh ve ((cua triet) OR (cua viet))*.