Perhaps you should try some spelling variations:
cau theo » cau thi, cau tao
sach thu » sach thue, sach thieu, sach tham
thu nang » thi nang, thu hang, thu bang
cau treo » cau tren, cau triet, cau trieu
doan van » doan va, hoang van, luan van
va doan » va doanh, van doan, va dan
tu sach » thu sach, su sach, te sach
ve cham » va cham, vu cham, ve chim
nang xa » nang x, lang xa, nang ma
ve chat » va chat, van chat

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 thu nang xa hoi. hieu ((ve cham) or (ve chat)) duc va doan van ((cau treo) OR (cau theo))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach thu nang xa hoi. hieu ((ve cham) OR (ve chat)) duc va doan van ((cau treo) OR (cau theo)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach thu nang xa hoi. hieu ((ve cham) or (ve chat)) duc va doan van ((cau treo) OR (cau theo))".
• Adding a wildcard symbol may retrieve word variants: tu sach thu nang xa hoi. hieu ((ve cham) or (ve chat)) duc va doan van ((cau treo) OR (cau theo))*.