Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
cua triet » cua viet, su triet, va triet
tu sach » thu sach, su sach, te sach
ky tang » ky dang, kho tang, ky trong
hieu le » hieu ve, hieu he, hieu ly
dan den » ban den, van den, dan dung
den cua » dien cua, de cua, ben cua
le cap » le cau
cuu va » cuu van, cuu ve
va dan » ca dan, va dao, va dau

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) or (thuoc sach)) ((ky tang) OR (ky nang)) xa hoi. hieu le cap cuu va dan den cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thuoc sach)) ((ky tang) OR (ky nang)) xa hoi. hieu le cap cuu va dan den cua triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (thuoc sach)) ((ky tang) OR (ky nang)) xa hoi. hieu le cap cuu va dan den cua triet".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (thuoc sach)) ((ky tang) OR (ky nang)) xa hoi. hieu le cap cuu va dan den cua triet*.