Perhaps you should try some spelling variations:
cau triet » cau trieu, su triet, cua triet
thanh lap » thanh san, phan lap, thanh hai
hanh lai » hanh lam, hanh tai, thanh loi
hieu van » hieu va, thien van, lieu va
tu sach » thu sach, su sach, te sach
hac duc » hoc duc, ha duc, thach duc
sach ky » sac ky, sach y, sach ty
van hac » van hoc, van ha, van hai
ma hoi » mai hoi, ma hoa, me hoi

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 ((ma hoi) OR (xa hoi)). hieu van hac duc va ((hanh lai) or (thanh lap)) cau triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang ((ma hoi) OR (xa hoi)). hieu van hac duc va ((hanh lai) OR (thanh lap)) cau triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang ((ma hoi) OR (xa hoi)). hieu van hac duc va ((hanh lai) or (thanh lap)) cau triet".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang ((ma hoi) OR (xa hoi)). hieu van hac duc va ((hanh lai) or (thanh lap)) cau triet*.