Perhaps you should try some spelling variations:
dang khai » dang khoi, dang hai, quang khai
dang thi » hoang thi, dang khoi
duc tran » duc tan, duc toan, duc tren
su sach » vu sach
cac duc » cac du, cao duc, cac dac
ca viet » va viet, co viet, hoa viet
hieu ve » hieu va, hieu van
so sach » so sanh, bo sach, co sach
anh xa » anh xay, canh xa, anh va
ky anh » ky danh, ly anh, ty anh
ve cac » va cac, vien cac

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

• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (so sach)) ky anh xa hoi. hieu ve cac duc tran ((dang thi) OR (dang khai)) ca viet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sach) OR (so sach)) ky anh xa hoi. hieu ve cac duc tran ((dang thi) or (dang khai)) ca viet~".
• Adding a wildcard symbol may retrieve word variants: ((su sach) OR (so sach)) ky anh xa hoi. hieu ve cac duc tran ((dang thi) or (dang khai)) ca viet*.