Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
hanh dau » hang dau, danh dau, han dau
van hanh » van thanh, ban hanh, van anh
dau cua » dai cua, day cua, cau cua
te sach » toc sach
hieu ve » hieu va, hieu van
sach 6 » sach y, sach 2
ma hoi » mai hoi, ma hoa, me hoi

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 6 tang ((ma hoi) or (xa hoi)). hieu ve ((nhan luc) OR (nang luc)) van hanh dau cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach 6 tang ((ma hoi) OR (xa hoi)). hieu ve ((nhan luc) OR (nang luc)) van hanh dau cua triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach 6 tang ((ma hoi) or (xa hoi)). hieu ve ((nhan luc) OR (nang luc)) van hanh dau cua triet".
• Adding a wildcard symbol may retrieve word variants: te sach 6 tang ((ma hoi) or (xa hoi)). hieu ve ((nhan luc) OR (nang luc)) van hanh dau cua triet*.