Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
qua pham » quan pham, quy pham, qua cham
tu sach » thu sach, su sach, tu cach
te sach » toc sach
ty nang » ky nang, ty xang, ty hang
nang ma » tang ma, sang ma, nang cao
hanh di » hanh de, hang di, danh di
ma hoi » mai hoi, xa hoi, ma hoa

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 (te sach)) ty nang ma hoi. hieu qua pham duc va ((hanh di) OR (hanh vi)) cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (te sach)) ty nang ma hoi. hieu qua pham duc va ((hanh di) OR (hanh vi)) cua triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (te sach)) ty nang ma hoi. hieu qua pham duc va ((hanh di) OR (hanh vi)) cua triet".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (te sach)) ty nang ma hoi. hieu qua pham duc va ((hanh di) OR (hanh vi)) cua triet*.