Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
thanh vi » hanh vi, thanh va, thanh ve
va thanh » gia thanh, ban thanh, va tinh
nam thuc » nam thuoc, nam thu, nam tu
sach ky » sac ky, sach y, sach ty
tu sach » thu sach, su sach, te sach
ky lang » ky nang, ky dang, ky tang
hieu ve » hieu va, hieu van
ha hoi » hoa hoi, ha noi, va hoi
vi cua » vai cua, di cua

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 lang ((ha hoi) or (xa hoi)). hieu ve ((nam thuc) OR (am thuc)) va thanh vi cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky lang ((ha hoi) OR (xa hoi)). hieu ve ((nam thuc) OR (am thuc)) va thanh vi cua triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky lang ((ha hoi) or (xa hoi)). hieu ve ((nam thuc) OR (am thuc)) va thanh vi cua triet".
• Adding a wildcard symbol may retrieve word variants: tu sach ky lang ((ha hoi) or (xa hoi)). hieu ve ((nam thuc) OR (am thuc)) va thanh vi cua triet*.