Perhaps you should try some spelling variations:
thanh gian » thanh giang, thach giang, thanh san
cua triet » cua viet, su triet, va triet
hinh giao » chinh giao, minh giao, tinh giao
thu sach » tu sach, thuat sach, thuoc sach
hieu ve » hieu va, hieu van
sach ky » sac ky, sach y, sach ty
duc van » duc va, duc tan, duc manh
cac duc » cac du, cao duc, cac dac
ve cac » va cac, vien cac
x hoi » o hoi, x ho, 5 hoi

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: thu sach ky nang ((x hoi) OR (xa hoi)). hieu ve cac duc van ((thanh gian) or (hinh giao)) cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ky nang ((x hoi) OR (xa hoi)). hieu ve cac duc van ((thanh gian) OR (hinh giao)) cua triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ky nang ((x hoi) OR (xa hoi)). hieu ve cac duc van ((thanh gian) or (hinh giao)) cua triet".
• Adding a wildcard symbol may retrieve word variants: thu sach ky nang ((x hoi) OR (xa hoi)). hieu ve cac duc van ((thanh gian) or (hinh giao)) cua triet*.