Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
tu sach » thu sach, su sach, te sach
ky lang » ky nang, ky dang, tay lang
ky tang » ky nang, ky dang, kho tang
hieu ve » hieu va, hieu van
cac toc » cac toi, cac nuoc, cac thoi
va hang » van hang, va nang, va lang
hang di » hang doi, hang vi, hang dien
ve cac » va cac, vien cac
toc va » hoc va, toc ta, tuc va
di cua » dai cua, doi cua, de 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) or (ky tang)) xa hoi. hieu ve cac toc va hang di cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((ky lang) OR (ky tang)) xa hoi. hieu ve cac toc va hang di cua triet.
• Adding a wildcard symbol may retrieve word variants: tu sach ((ky lang) or (ky tang)) xa hoi. hieu ve cac toc va hang di cua triet*.