Perhaps you should try some spelling variations:
cau tren » cu tren, dau tren, ca tren
lang xa » dang xay, lang van
lang ha » long ha
sach ty » sach y, sach tu, sach thu
va hanh » van hanh, va thanh, va danh
cua tre » cua te, cuu tre, cua triet
so sach » so sanh, bo sach, co sach
hieu v » hieu va, hieu ve, hieu 2
v pham » vi pham, d pham

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

• Performing a fuzzy search may retrieve terms with similar spellings: so sach ty ((lang xa) OR (lang ha)) hoi. hieu v pham duc va hanh vi ((cua tre) or (cau tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ty ((lang xa) OR (lang ha)) hoi. hieu v pham duc va hanh vi ((cua tre) OR (cau tren))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach ty ((lang xa) OR (lang ha)) hoi. hieu v pham duc va hanh vi ((cua tre) or (cau tren))*".