Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
toc sach » hoc sach, doc sach, thuoc sach
nang xa » nang x, nang ma, mang xa
lang xa » lang ha, dang xay, lang van
hieu ve » hieu va, hieu van
sach vu » sach va, sach tu, sach uu
va dan » ca dan, va dao, va dau
dan le » ban le, van le, dan ve
le cua » ly cua

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 vu ((nang xa) or (lang xa)) hoi. hieu ve ((cham soc) or (cham o)) va dan le cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach vu ((nang xa) OR (lang xa)) hoi. hieu ve ((cham soc) OR (cham o)) va dan le cua triet.
• Adding a wildcard symbol may retrieve word variants: toc sach vu ((nang xa) or (lang xa)) hoi. hieu ve ((cham soc) or (cham o)) va dan le cua triet*.