Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
hieu van » hieu va, thien van, lieu va
va thanh » gia thanh, ban thanh, le thanh
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
van cau » van dau, van hau, van chat
cau duc » cao duc, cau luc, chu duc
va tinh » may tinh
lam cua » nam cua, lam chat
nang o » nang co, nang ho, nang ro
o hai » co hai, so hai, o lai

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 nang o hai. hieu van cau duc ((va thanh) or (va tinh)) lam cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang o hai. hieu van cau duc ((va thanh) OR (va tinh)) lam cua triet.
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang o hai. hieu van cau duc ((va thanh) or (va tinh)) lam cua triet*.