Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
hanh vai » hanh vi, hanh tai, hanh van
toc sach » hoc sach, doc sach, thuoc sach
hieu ve » hieu va, hieu van
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
hanh va » hang va, hanh vi
ve cac » va cac, vien cac
lo van » le van, vo van, do van
so van » su van, vo van

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: toc sach ky nang xa hoi. hieu ve cac ((lo van) OR (so van)) ((hanh vai) or (hanh va)) cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ky nang xa hoi. hieu ve cac ((lo van) OR (so van)) ((hanh vai) OR (hanh va)) cua triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ky nang xa hoi. hieu ve cac ((lo van) OR (so van)) ((hanh vai) or (hanh va)) cua triet".
• Adding a wildcard symbol may retrieve word variants: toc sach ky nang xa hoi. hieu ve cac ((lo van) OR (so van)) ((hanh vai) or (hanh va)) cua triet*.