Perhaps you should try some spelling variations:
tu sach » thu sach, su sach, te sach
hanh ve » hanh vi, hanh va, hanh kem
duc ban » duc tan, duc van, dua ban
hieu ve » hieu va, hieu van
su tien » su kien, su hien, tu tieng
va nang » van nang, da nang, cam nang
v nang » vu nang, van nang, voi nang
ve cac » va cac, vien cac
x hoi » xa hoi, o hoi, x ho
ve su » va su

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 (va nang)) x hoi. hieu ve cac ((duc ban) or (qua quan)) hanh ve su tien~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((v nang) OR (va nang)) x hoi. hieu ve cac ((duc ban) OR (qua quan)) hanh ve su tien*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((v nang) OR (va nang)) x hoi. hieu ve cac ((duc ban) or (qua quan)) hanh ve su tien*".