Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
hanh vai » hanh va, hanh tai, hanh van
cac tuc » cac toc, cac tu, cac tac
tu sach » thu sach, su sach, te sach
hieu ve » hieu va, hieu van
mai hoi » mai khoi, dai hoi, lai hoi
ky sang » ky dang, ky tang, duy sang
tuc va » thuc va, truc va, tuc xa
ve cac » va cac, vien cac

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 sang) or (ky nang)) mai hoi. hieu ve cac tuc va ((hanh vai) OR (hanh vi)) cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((ky sang) OR (ky nang)) mai hoi. hieu ve cac tuc va ((hanh vai) OR (hanh vi)) cua triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((ky sang) or (ky nang)) mai hoi. hieu ve cac tuc va ((hanh vai) OR (hanh vi)) cua triet".
• Adding a wildcard symbol may retrieve word variants: tu sach ((ky sang) or (ky nang)) mai hoi. hieu ve cac tuc va ((hanh vai) OR (hanh vi)) cua triet*.