Perhaps you should try some spelling variations:
hieu thien » hieu hien, chieu chien, dieu khien
cua triet » cua viet, su triet, va triet
thien cac » hien cac, thien cau, thieu cac
van nang » van quang, van ban, van dong
hang vai » hang tai, hang hai, hang vi
cac duc » cac du, cao duc, cac dac
duc ban » duc tan, duc van, dua ban
tu sach » thu sach, su sach, te sach
v nang » va nang, vu nang, voi nang
x hoi » xa hoi, o hoi, x ho

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 ((v nang) OR (van nang)) x hoi. hieu thien cac duc ban ((hang vai) or (hang va)) cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((v nang) OR (van nang)) x hoi. hieu thien cac duc ban ((hang vai) OR (hang va)) cua triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((v nang) OR (van nang)) x hoi. hieu thien cac duc ban ((hang vai) or (hang va)) cua triet".
• Adding a wildcard symbol may retrieve word variants: tu sach ((v nang) OR (van nang)) x hoi. hieu thien cac duc ban ((hang vai) or (hang va)) cua triet*.