Perhaps you should try some spelling variations:
thien van » thi van
thu sach » thuat sach, thuoc sach, thu hoach
xay hoi » xa hoi, tay hoi, cay phoi
van cau » van dau, van hau, van chat
lai cua » dai cua, lai chau, thai cua
hai cua » thai cua, dai cua, hoi cua
tu sach » su sach, te sach, tu cach
ky van » ly van, ty van, ky va
cau tu » dau tu, cau truc
tu gia » tu giao, tu giac, tu giay

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) OR (thu sach)) ky van xay hoi. thien van cau tu gia thanh ((lai cua) or (hai cua)) triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thu sach)) ky van xay hoi. thien van cau tu gia thanh ((lai cua) OR (hai cua)) triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) OR (thu sach)) ky van xay hoi. thien van cau tu gia thanh ((lai cua) or (hai cua)) triet".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) OR (thu sach)) ky van xay hoi. thien van cau tu gia thanh ((lai cua) or (hai cua)) triet*.