Perhaps you should try some spelling variations:
nang khai » dang khai, nang hai, quang khai
sach hoa » sach ha, sach hoi, bach hoa
cau theo » cau thi, cau tao
su sach » so sach, vu sach
hieu ve » hieu va, hieu van
ve cham » va cham, ve chat, vu cham
cua tre » cua te, cuu tre, cua triet
dan xa » dan xac, dan xay, dan ca
soc va » loc va, doc va, goc va

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 hoa dan xa hoi. hieu ve cham ((soc va) OR (hoc va)) nang khai ((cua tre) OR (cau theo))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach hoa dan xa hoi. hieu ve cham ((soc va) OR (hoc va)) nang khai ((cua tre) or (cau theo))~".
• Adding a wildcard symbol may retrieve word variants: su sach hoa dan xa hoi. hieu ve cham ((soc va) OR (hoc va)) nang khai ((cua tre) or (cau theo))*.