Perhaps you should try some spelling variations:
cau tren » cu tren, dau tren, ca tren
thanh vi » hanh vi, thanh va, thanh ve
sach ty » sach y, sach tu, sach thu
cuu tre » cua tre, cau treo
su sach » so sach, vu sach
hieu va » lieu va, hieu qua
mang xa » lang xa, mang may, dang xay
ty mang » ty xang, ty hang, tin mang
dac va » duc va, day va, dai va

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach ty mang xa hoi. hieu va cac ((dac va) OR (dat va)) thanh vi ((cuu tre) or (cau tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ty mang xa hoi. hieu va cac ((dac va) OR (dat va)) thanh vi ((cuu tre) OR (cau tren))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ty mang xa hoi. hieu va cac ((dac va) OR (dat va)) thanh vi ((cuu tre) or (cau tren))*".