Perhaps you should try some spelling variations:
cau tren » cu tren, dau tren, ca tren
su sach » so sach, vu sach
sach ty » sach y, sach tu, sach thu
xang xa » lang xa, mang xa, ang xa
hieu vi » hieu voi, hieu va, hieu ve
cua tre » cua te, cua triet, dua tren
cuu tre » cau treo
va dan » ca dan, va dao, va dau
dan vi » doan vi, don vi, dan va
pham » phan

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 xang xa hoi. hieu vi pham duc va dan vi ((((cua tre) or (cuu tre))) or (cau tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ty xang xa hoi. hieu vi pham duc va dan vi ((((cua tre) OR (cuu tre))) OR (cau tren)).
• Adding a wildcard symbol may retrieve word variants: su sach ty xang xa hoi. hieu vi pham duc va dan vi ((((cua tre) or (cuu tre))) or (cau tren))*.